JP3422817B2 - Preloading device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preload applying device. 2. Description of the Related Art In various works such as a pivot and a spindle motor using an adhesive-fixed type bearing, a preload is applied to the bearing in order to prevent rattling of the bearing. Weight of weight (weight)
The preload was applied by a batch type preload unit configured to apply a specified preload to the bearing. [0003] However, in the batch system, the station is occupied during the preload time, so that the efficiency is low. Therefore, a plurality of pallets on which a work with a preload is placed are conveyed by a conveyor, and the conveyance time is used as the preload time. [0004] However, in the above-mentioned weight type preload unit, inertia force acts on the weight as the pallet moves, and the preload fluctuates, so that a stable preload cannot be applied. There was a problem. Accordingly, an object of the present invention is to provide a preload applying device capable of applying a stable preload to a work. In order to achieve the above object, the present invention provides a transport pallet 2 on which a work 1 to be preloaded is detachably mounted and transported, A holding member 3 movably provided up and down on the transfer pallet 2 so as to be vertically driven by a driving means 60 provided at a predetermined position on the transfer path; and a holding member 3 held movably up and down by the holding member 3. a pressing member 4 abuts on the work 1 by the drop of the member 3, a compression spring 5 applying a preload force to the workpiece 1 and the pressing pressure body 4 resiliently urging downward against the holding member, the transport Set at a specific position on the pallet 2 transport path
And a clamp means 6 provided on the transport pallet 2 so as to maintain the holding member 3 at a predetermined vertical position by the lifted and lowered means 61 and maintain a state of applying a preload to the work 1. It is. When the pressing member comes into contact with the work mounted on the transport pallet by the lowering of the holding member, the compression spring is compressed and the pressing body is elastically urged downward, so that the work is fixed to the work. Pressure is applied. Then, the transport pallet is transported while the preload applied state to the work is maintained by the clamp means, and a preload is applied to the work during the transport time. As described above, if a preload is applied to a work using a compression spring, even if the transport pallet moves, no inertial force acts unlike the conventional weight type, so that the preload is reduced. A stable preload can be applied to the work without fluctuation. The present invention will be described below in detail with reference to the drawings showing embodiments. FIGS. 1, 2 and 3 show a preloading device according to the present invention. The preloading device includes a transport pallet 2 on which a work 1 to be preloaded is removably mounted and transported. A holding member 3 movably provided on the transport pallet 2, and a pressing member 4 held by the holding member 3 so as to be vertically movable and abutting on the workpiece 1 when the holding member 3 descends.
Then, a compression spring 5 for urging the pressing body 4 downward to apply a preload to the work 1 and a holding member 3 at a predetermined vertical position to maintain the preload applied state to the work 1. And a clamping means 6 provided on the transport pallet 2. The transport pallet 2 comprises a horizontal lower plate 7, inverted L-shaped support plates 8, 8 erected on both ends of the lower plate 7, and upper end surfaces of the support plates 8, 8. , And a horizontal upper plate 9 fixed to the upper surface. A plurality of (three in the illustrated example) mounting holes 11 are formed in the lower plate 7 in the vertical direction, and a cylindrical work holder 10 is removably mounted in the mounting holes 11. The work holder 10 has a small-diameter portion 12 and a large-diameter portion 13. The small-diameter portion 12 is inserted into a mounting hole 11, and a stepped surface 14 between the small-diameter portion 12 and the large-diameter portion 13 is a lower plate. 7 is positioned in contact with the upper surface. On the outer peripheral surface of the small diameter portion 12, a concave peripheral groove 15 into which an O-ring or the like is fitted is formed. Further, a concave portion 16 having a predetermined depth is formed at an upper end portion of the large diameter portion 13.
An annular ridge 17 is projected from the bottom surface of 16 upward. The work 1 has a shaft member 19 having a male thread 18.
And a pair of bearings 20, 21 such as a pair of ball bearings fitted on the outer peripheral surface 19a of the shaft member 19, and outer rings 20a,
A ring member 22 interposed between the shaft members 21a.
A tapered hole 23 for centering is formed in the tip end surface of 19. The male screw portion 18 of the work 1 is inserted into the center hole 24 of the work holder 10, and the lower bearing 21 is inserted into the recess 16 so that the inner ring 21b of the bearing 21 is located on the outer side in the axial direction. The end face is set in contact with the top of the ridge 17. In the illustrated work 1, the adhesive applied to the inner peripheral surface of the inner race 21 b of the lower bearing 21 and the outer peripheral surface 19 a of the shaft member 19 is solidified, and the inner race 20 b of the upper bearing 20 is solidified. The work 1 is set on the work holder 10 in a state in which the adhesive applied to the inner peripheral surface of the shaft member 19 and the outer peripheral surface 19a of the shaft member 19 is not solidified, and a preload is applied. Next, a plurality (three in the illustrated example) of outer ball bushes 26 are attached to the upper plate 9 by mounting pieces 25 in a vertically penetrating manner.
Then, the holding member 3 is held so as to be vertically movable. The holding member 3 includes a cylindrical shaft 27 and a flanged lid fixed to the upper end of the shaft 27 with bolts or the like.
28, a movable boss 29 slidably fitted on the upper end side of the inner peripheral surface of the shaft 27, and C near the lower end of the inner peripheral surface of the shaft 27.
Inner ball bush 31 fixed with retaining ring 30 such as ring
The inner ball bush 31 holds a hollow collar shaft 32 so as to be vertically movable. A screw hole 33 is formed in the cover 28 in a vertical direction, and a preload adjusting bolt 34 whose tip is in contact with the upper end surface of the movable boss 29 is screwed into the screw hole 33. . 35 is
It is a nut for clamping the bolt 34. Next, a stop ring 36 such as a C-ring is attached to the outer peripheral surface on the upper end side of the color shaft 32. This snap ring
The compression spring 5 is interposed between the movable boss 29 and the movable boss 29, and the color shaft 32 is constantly urged downward by the compression spring 5. An upper bush 38 is provided at the upper end of the shaft hole 37 of the collar shaft 32. Further, the lower end of the collar shaft 32 is provided with a pressing body 4 via a lower bush 39.
Is attached, and the color shaft 32 and the pressing body 4 are integrated,
It moves up and down and is always urged downward by the compression spring 5. That is, the pressing body 4 has a cylindrical shape that can be inserted into the shaft 27 and has a large-diameter shaft hole 40 and a small-diameter shaft hole 41. The lower end of the bush 39 is inserted and fixed with a bolt or the like. The pressing body 4 has a downwardly projecting peripheral projection 44 on its lower end surface, and the top of the pressing body 4 is
The inner ring 20b of the bearing 20 of the workpiece 1 set to 10 is brought into contact with only the axially outer end face. Reference numeral 42 denotes a center pin having an outer flange 43.
The center pin 42 is slidably inserted into the upper and lower bushes 38 and 39, and penetrates the pressing body 4 and the collar shaft 32. The lower end portion 46 of the color shaft 32 is formed in a hemispherical shape, and the lower end portion 46 comes into contact with the tapered hole 23 of the work 1 set on the work holder 10. A compression spring 45 is interposed between the outer flange 43 of the center pin 42 and the movable boss 29.
The center pin 42 is constantly urged downward by 45. As described above, the pressing body 4 and the collar shaft 32 can move up and down relatively with respect to the holding member 3.
Further, the center pin 42 is connected to the pressing body 4 and the collar shaft.
32 and the holding member 3 can be moved up and down relatively. In a state where the center pin 42 and the pressing body 4 do not contact the work 1, the retaining ring 36 attached to the collar shaft 32 contacts the upper surface of the inner ball bush 31, and the outer side of the center pin 42. The flange 43 contacts the upper end surface of the collar shaft 32, and the center pin 42 and the pressing body 4 move up and down integrally with the holding member 3. In addition, the downward movement of the holding member 3 is performed by using a cover.
The lower end surface 47 of the ball 28 is regulated by contact with the upper surface of the outer ball bush 26. However, after the pressing body 4 comes into contact with the work 1, a predetermined stroke H (see FIG.
Only), the holding member 3 moves downward,
The lower end surface 47 is configured to come into contact with the upper surface of the outer ball bush 26 to be in the lowest state. As described above, when the holding member 3 moves down by the stroke H, the compression spring 5 is compressed, and the pressing body 4 is elastically urged downward, so that the bearings 20 and
At 21 a prescribed preload is applied. Next, an L-shaped block body 48 is provided on each of the support plates 8, 8 corresponding to each holding member 3. Therefore, in the illustrated transport pallet 2, three block bodies 48 are provided. The lower end of the block body 48 is connected to a pivot bar 49.
Are attached to the support plates 8, 8 so as to be swingable around the horizontal axis A. A fixing member 50 such as a bolt and nut is protruded from the upper and lower intermediate portions of the block body 48.
A tension spring 52 is interposed between the upper plate 9 and a fixture 51 such as a bolt and nut provided on the upper plate 9. The block body 48 is constantly resiliently urged in the direction of arrow C (see FIG. 2) by a tension spring 52. For example, the end face 53 of the block body 48 is attached to the end face 53 of the upper plate 9 or the mounting piece 25.
Or the block 48 is brought into contact with a stopper or the like (not shown) to maintain the state shown by the solid line in FIG. The block body 48 has a lock projection 55 and an operation projection 56 projecting in opposite directions at upper and lower ends thereof. It is maintained (clamped) in position. That is, the lower surface of the flange portion 57 of the lid 28 abuts on the upper end surface of the lock projection 55, and the holding member 3 is retracted upward as shown by the phantom line in FIG. Hereinafter, this is referred to as a retracted state).
The upper surface of the flange portion 57 of the lid 28 abuts on the lower end surface of
As shown by the solid line in FIG. 3, the holding member 3 is lowered to the lowest position, and a state in which a prescribed preload is applied to the work 1 as described above (hereinafter referred to as a preload applied state) is maintained. The clamping means 6 is constituted by the block body 48, the pivot bar 49, the tension spring 52 and the like. A plurality of transport pallets 2 are provided,
The rollers are sequentially conveyed along a loop-shaped conveying path provided with a conveyor 59 using rollers 58. Although not shown, at a predetermined position on the transport path,
A set station for applying a preload to the work 1 set on the transport pallet 2 and a reset station for removing the work 1 to which the preload has been applied from the transport pallet 2 are provided. As shown in FIGS. 2 and 4, the set station and the reset station include a driving means 60 for vertically moving the holding member 3 and an elevating means 61 for swinging the block 48 in the direction of arrow B. Provided. The driving means 60 includes a pair of parallel and horizontal projections.
A hook member 63 having 62, 62, and a driving device such as a cylinder (not shown) for raising and lowering the hook member 63 and rotating the hook member 63 about the vertical axis D are provided. The pair of projections 62 of the hook member 63 correspond to the flange portion 57 of the lid 28 of the holding member 3, and the vertical axis D
By rotating it around, a pair of protrusions 6
The holding members 3 can be moved up and down by engaging and disengaging the two and 62. The elevating means 61 is provided with a vertical pressing bar 64.
And a driving device such as a cylinder (not shown) for raising and lowering the pressing bar 64. At the lower end of the pressing bar 64, the block 48
By pushing down the operation protrusion 56 of the block 48, the lock protrusion 55 of the block body 48 can be swung in the direction of arrow B against the elastic force of the tension spring 52. Due to this, the locking projection
55, the clamping of the holding member 3 by the holding member 3 is released.
Can be freely raised and lowered by the lifting means 61. Incidentally, the hook member 63 and the pressing bar 64 are formed by the holding member 3 provided on one transport pallet 2 and the block body.
It is provided corresponding to each of the 48 numbers. Therefore, in each station, three hook members 63... And three pressing bars 64 are provided.
... is arranged. Further, in each station, each hook member 63 and each pressing bar 64 are configured to be driven independently, or in the reset station, all the hook members 63 are interlocked. It may be configured to be driven and to drive all the pressing bars 64 in conjunction with each other. An example of a procedure for applying a preload to the work 1 by the preload applying device configured as described above will be described. As shown in FIGS. 1, 2 and 3, when the transport pallet 2 on which the work 1 is not set is transported by the conveyor 59 and stopped short of the set station, the adhesive Is set on the work holder 10 of the transport pallet 2. At this time, in the reset station, each holding member 3 (as shown by the phantom line in FIG. 2)
Is maintained in the retracted state by the lock projection 55 of the block body 48. Thereafter, the transport pallet 2 is sent to the set station, where the pair of projections 62 of the hook member 63 is engaged with the flange portion 57 of the lid 28 of the holding member 3 at the set station. The pressing bar 64 descends, and the lock projection 55 is separated from the holding member 3. When the holding member 3 is lowered by the hook member 63, first, the lower end portion 46 of the center pin 42 comes into contact with the tapered hole 23 of the shaft member 19 of the work 1, and the centering with the work 1 is performed. Is performed, and then the peripheral protrusion 44 of the pressing body 4
Abuts on the inner ring 20b of the upper bearing 20 of the work 1. When the holding member 3 reaches the lowest position,
A prescribed preload is applied to the bearings 20 and 21 of the work 1 by the compression spring 5, and the pressing bar 64 is raised, as shown in FIG.
The lock projection 55 is returned to the original state by the tension spring 52, and the holding member 3 is clamped, and the preloaded state is maintained (as shown by the solid line in FIG. 3). Thus, the inner ring 20 of the upper bearing 20
b is pressed downward, and the inner ring 20b and the outer ring 20a
And the outer ring 21a of the lower bearing 21 is pressed through the ring body 22 so that the outer ring 21a and the inner ring
21b comes into pressure contact with the ball 21c. Since the application of the adhesive to the work 1 is performed one by one, the adhesive is applied to the work 1 one by one so that the time from the application of the adhesive to the application of the preload is constant. Preload is applied in the order of application. Next, the work 1 in which the preloaded state is maintained
Transport pallet 2 on which the conveyor 59
When the adhesive applied to the upper bearing 20 flows upward and solidifies, the inner rings 20b and 21b of the bearings 20 and 21 are in a state where a preload is applied in a direction approaching each other. When the transport pallet 2 stops at the reset station, the pair of projections 62 of the hook member 63 is engaged with the flange portion 57 of the lid 28 of the holding member 3, and the pressing bar 64 is lowered to hold the pallet. The lock projection 55 is detached from the member 3, the holding member 3 is raised by the hook member 63, and the preloaded state is released. Then, the work 1 to which the preload is applied is taken out from the work holder 10 of the transport pallet 2. In the reset station, the three preload applied states are simultaneously released. As described above, the work 1 is formed by using the compression spring 5.
If the pre-load is applied, even if the transport pallet 2 moves abruptly, the inertia force (due to acceleration / deceleration) does not act unlike the conventional weight type, so that the pre-load does not fluctuate and is stable. Preload can be applied. When the preload is applied not by the compression spring 5 but by a tension spring, when the preload is applied, the tension spring must be extended extra and then returned. Therefore, the preload decreases from the value exceeding the specified value to the specified value, and the impact force when returning from the overload to the specified value is also applied to the bearing, causing an overload state of the preload. That is, in the present invention, the preload increases from a small value to reach the specified value, and the impact force is not applied, so that the preload does not become overloaded. Since the present invention is configured as described above, the following significant effects can be obtained. Since the preload is applied to the work 1 by the compression spring 5, the preload does not fluctuate even when the transport pallet 2 moves, and a stable preload is applied as compared with the weight type. In addition, it is easy to adjust the setting of the prescribed value of the preload and the cost is not increased. In the compression spring 5, the preload increases from a small value and reaches a specified value. Further, since no impact force is applied when the preload is applied, the preload is applied using a tension spring. As compared with the above structure, the preload is not overloaded, and the quality is good. Further, the preload can be reliably applied to the work by the clamping means 6, and the preload can be quickly applied and released.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing one embodiment of the present invention. FIG. 2 is a side view. FIG. 3 is an enlarged sectional view of a main part. FIG. 4 is a simplified explanatory view of the movement of the hook member as viewed from above. [Description of Signs] 1 work 2 transport pallet 3 holding member 4 pressing body 5 compression spring 6 clamping means 60 driving means

Continuation of front page (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 15/14 B23P 21/00 F16C 43/04

Claims (1)

(1) A transport pallet (2) on which a work (1) to be preloaded is detachably mounted and transported, and a drive provided at a predetermined position on a transport path of the transport pallet (2). A holding member 3 movably provided up and down on the transport pallet 2 so as to be driven up and down by means 60; a pressing member 4 which is in contact, a compression spring 5 applying a preload force to the workpiece 1 by resiliently urging downward the pressing pressure body 4 relative to the holding member, provided at a specific position of the transfer path of the conveying pallet 2 La
Clamping means 6 provided on the transport pallet 2 so as to maintain the holding member 3 at a predetermined vertical position by the lifted and lowered means 61 and maintain a state of applying a preload to the work 1. A preload applying device characterized by the above-mentioned.