JP2007120760A - Circulating part presser and ball screw device provided with the presser - Google Patents

Abstract

Provided is a circulating component presser capable of increasing the speed and durability of a ball screw device.
A presser for fixing a circulating component 27 having both ends fitted to a pair of circulating holes 34 provided on a side surface of a nut 24 with a ball 25 rolling in a load region of the ball screw device. A main body 41 formed by deep drawing and covering the circulating component 27; a fixing seat portion 42 formed by folding back the opening end of the main body 41 on the nut 24 side; and the main body 41 And a reinforcing portion 43 formed by folding back an opening end other than the seat portion 42 on the nut 24 side to the outside with a shorter length than the seat portion 42.
[Selection] Figure 3

Description

  The present invention relates to a presser for fixing a circulating part of a ball screw device used in various industrial machines, for example, and a ball screw device including the presser.

FIG. 10 shows a conventional tube circulation type ball screw device. This ball screw device 1 corresponds to a screw shaft 3 having a helical screw groove 2 on the outer peripheral surface and to a screw groove 2 on the inner peripheral surface. A nut 6 having a helical thread groove 4 is screwed.
The screw groove 4 of the nut 6 and the screw groove 2 of the screw shaft 3 are opposed to each other to form a spiral load region between them, and a large number of balls 5 as rolling elements are formed in the load region. It is loaded so that it can roll. The nut 6 (or the screw shaft 3) is moved in the axial direction through the rolling of the ball 5 by the rotation of the screw shaft 3 (or the nut 6).

  A part of the side surface of the nut 6 is a flat surface, and a set of two circulation holes 7 communicating between the screw grooves 2 and 4 are formed on the flat surface so as to straddle the screw shaft 3. The balls 5 revolving along the load region between the screw grooves 2 and 4 are fitted into the circulating parts 8 by fitting both ends of a substantially U-shaped tubular circulating part 8 into the set of circulating holes 7. A ball circulation path is formed by scooping up from one end of the lead and guiding it to the outside of the nut 6 and returning from the other end to the load region.

  In order to fix the circulating component 8 to the flat surface of the nut 6, a presser 9 as shown in FIG. 11 is used. The presser 9 is manufactured by sheet metal press working for mass production at a low cost. As shown in FIGS. 12 to 14, the presser 9 is circulated substantially at the center of the lower surface of the metal plate that is long in the axial direction of the nut 6. A groove 9 a for fitting into the component 8 to press the circulating component 8 is formed obliquely along the axial direction of the circulating component 8. Moreover, the both sides of the groove part 9a are made into the seat part 9b, The screw insertion hole 9c is formed in this seat part 9b.

Then, the groove 9a of the presser 9 is fitted into the circulating component 8, and in this state, the screw 9d inserted into the screw insertion hole 9c is tightened into a screw hole (not shown) provided on the flat surface of the nut 6. The circulating component 8 is fixed to the nut 6.
By the way, in such a tube-type circulation part, since the ball is completely separated from the screw groove of the nut from the side of the nut and it is an external circulation system that can be multi-rowed, especially high load capacity of small lead products However, with the recent increase in the speed of the ball screw device, the speed at which the ball collides with the circulating component increases and the collision energy increases, so that the circulating component and the thread groove (such as both shoulders of the screw groove) Therefore, it has been proposed that the ball scooping direction by circulating parts is inclined in the tangential direction of the screw shaft and in the lead angle direction (see, for example, Patent Document 1). ).

  In this ball screw device, the circulation part is made of a synthetic resin. As shown in FIG. 15, the circulation part 10 includes a pair of legs 11 fitted in a pair of circulation holes 7 of the nut 6. And a main body 12 for connecting the pair of leg portions 11, and the ball circulation path in the leg portion 11 is inclined so as to substantially coincide with the tangential direction of the spiral track between the screw grooves 2 and 4. And is divided into two in the radial direction with point symmetry, and a circulation groove 15 constituting the ball circulation path 10a is formed on the divided surface.

In order to fix the circulating component 10 to the nut 6, the circulating component 10 is directly fixed to the nut 6 via a screw or the like.
Japanese Patent Laid-Open No. 2003-232421

  In the conventional tube circulation type ball screw device, for example, there is an error in the mounting of the ball screw device, or a large moment load is applied to the ball screw device due to insufficient rigidity of the machine incorporating the ball screw device. In other applications, the revolving speed of the ball 5 varies depending on the location, so that the ball 5 is clogged in the circulating component 8, and the ball 5 may push up the circulating component 8. When such a force is applied to the circulating component 8, the presser 9 manufactured by sheet metal pressing is likely to deform the seat portion 9 b in contact with the flat surface of the nut 6, and the circulating component 8 may be lifted. is there.

As a measure to prevent the circulating parts 8 from being lifted up, it was manufactured by cutting out a block-shaped steel material in applications where the strength of the presser was required by a large ball screw device using a large-diameter ball (steel ball). Although the presser is used, since each presser is manufactured by machining, there is a problem that the processing cost is high.
On the other hand, in the ball screw device described in Patent Document 1, since the circulating component 10 is directly fixed to the nut 6 via a screw or the like, the screwed plastic circulating component 10 is creep-deformed to tighten the screw. May loosen.

Therefore, in order to eliminate these disadvantages, the present applicants have previously proposed a circulating part presser described in Japanese Patent Application No. 2003-370978.
As shown in FIG. 16, the presser 50 is formed by subjecting a metal plate material to a deep drawing process using a press, and substantially the entire area exposed in the side surface of the nut of the circulating component (in this example, the entire area). A cap-shaped main body 51 for covering, a fixing seat portion 52 formed by folding back the opening ends on the nut side at both side positions in the width direction of the main body 51, an upper surface of the seat portion 52, and a side surface of the main body 51 And a reinforcing rib 70 provided between them, and a screw insertion hole 53 is formed in the seat portion 52.

Then, the body 51 of the presser 50 is fitted into the circulating component, and in this state, the circulating component is fixed to the nut by tightening the screw inserted through the screw insertion hole 53 into the screw hole provided on the flat surface of the nut.
In such a structure, even if the ball causes a poor circulation in the circulation part and the circulation part is pushed from the inside, substantially the entire area of the circulation part is covered with the main body 51 of the metal presser 50. Therefore, it is possible to prevent the circulating component from being lifted, and to reduce the noise by blocking the sound transmitted through the circulating component and emitted to the outside.

  In addition, since the seat 52 of the metal presser 50 is screwed and fixed to the nut, and the seat 52 is reinforced by the reinforcing rib 70, the screw is tightened by creep deformation of the resin circulating component. There is no risk of loosening and the like, and the circulating component can be reliably and easily fixed to the nut. Furthermore, since the presser 50 is formed by deep drawing of a metal plate, mass production is possible at low cost.

  However, when the presser 50 having the shape shown in FIG. 16 is manufactured, the shape of the main body 51 is usually formed by deep drawing, and a portion 54 (FIG. 17 (a) protruding outward from the opening end side of the nut of the main body 51 is formed. )) Is cut along the side surface of the main body 51 leaving the seat 52 (see FIG. 17B). As can be seen from FIG. 17, in the case of such processing, R (see FIG. 17B) remains in the inner part of the opening end on the nut side of the main body 51 of the presser 50, and as a result, the tip is thin. It becomes a pointed shape. For this reason, in the presser 50 shown in FIG. 16, the thickness of the opening end on the nut side of the main body 51 other than the seat portion 52 becomes thin due to manufacturing, and the strength is insufficient. When an excessive force is applied due to a clogged ball or the like, cracks or the like may occur particularly at the opening end of the nut 51 near the seat 52 of the main body 51.

In addition, in the conventional circulating part presser including the presser 50 shown in FIG. 16, for example, when the diameter of the screw shaft is D and the rotational speed is N, D × N <10 ^When used at a low speed of about ⁵ or when a ball having a diameter of 8 mm or less is used as a rolling element, the possibility of damage is low. However, when used at a higher speed and when a large-diameter ball is used, the repeated stress applied to the presser and the number of repetitions increase. There is a possibility that cracks and the like will occur and eventually be damaged.
The present invention has been made to eliminate such inconveniences, and provides a retainer for circulating parts and a ball screw device provided with the retainer that can increase the speed and durability of the ball screw device. The purpose is to provide.

In order to achieve the above object, the invention according to claim 1 is a rolling element that rolls in a load region between a screw groove of a screw shaft of a ball screw device and a screw groove of a nut screwed into the screw shaft. Is formed inside the rolling element circulation path from one of the circulation holes provided on the side surface of the nut to the outside of the nut and returning from the other circulation hole to the load region. A presser for fixing a circulating component having both ends fitted to each circulation hole,
A main body that is formed by deep drawing and covers the circulating component, a fixing seat formed by folding the nut-side opening end of the main body outward, and the seat on the nut side of the main body And a reinforcing portion formed by folding the opening end outward with a shorter length than the seat portion.

The invention according to claim 2 is characterized in that, in claim 1, the folded length of the reinforcing portion is 0.5 to 5 times the plate thickness in a portion excluding the seat portion.
The invention according to claim 3 is the invention according to claim 1 or 2, wherein the length in the circumferential direction of the opening end on the nut side of the folded portion of the reinforcing portion and the seat portion is 90% or more of the entire circumference of the opening end. It is characterized by that.

The invention according to a fourth aspect is the stress according to any one of the first to third aspects, wherein the stress applied between the main body and the seat portion is relaxed in the vicinity of the seat portion of the main body and the reinforcing portion. A relaxation portion is formed.
The invention according to claim 5 is characterized in that, in claim 4, the stress relieving part is constituted by a notch that continues the boundary between the seat part and the reinforcing part.
The invention according to claim 6 is characterized in that, in any one of claims 1 to 5, the material of the presser is a stainless material having a tensile strength of 40 kgf / mm ² or more.

The invention according to a seventh aspect is the invention according to any one of the first to sixth aspects, wherein the presser is in contact with the circulating component on a continuous surface including a central portion of the circulating component,
When the length along the length direction of the circulating component at the contact portion of the presser with the circulating component is CL, the length of the circulating component is L, and the width of the circulating component is W, L The condition expression −3W ≦ CL ≦ L−W is satisfied.

According to an eighth aspect of the present invention, there is provided a screw shaft having a spiral thread groove on the outer peripheral surface, and a spiral thread groove corresponding to the screw groove of the screw shaft on the inner peripheral surface, and screwing into the screw shaft. A set of two provided on the side surface of the nut, and a number of rolling elements loaded in a load area between the screw grooves so as to be able to roll, and the rolling elements rolling in the load area. One end of each of the circulation holes is guided to the outside of the nut, and both ends are fitted to the respective circulation holes so as to form a rolling element circulation path to return to the load region from the other circulation hole. In a ball screw device including a circulating component and a presser for fixing the circulating component,
The presser according to any one of claims 1 to 7 is used as the presser.
The invention according to claim 9 is the invention according to claim 8, wherein the circulating component has leg portions fitted to the circulation holes of the nut at both ends, and the passage of the rolling element in the leg portion is the leg. It is characterized by being inclined with respect to the outer peripheral surface of the part.

  According to the present invention, a main body formed by deep drawing and covering a circulating component, a fixing seat formed by folding the nut-side opening end of the main body outward, and a nut-side seat of the main body Since it is provided with a reinforcing portion formed by folding the opening end other than the seat portion to the outside with a shorter length than the seat portion, the thickness of the opening end other than the seat portion on the nut side of the main body can be increased, Further, the strength of the entire presser can be increased by the reinforcing portion by folding. As a result, it is possible to prevent the presser from being damaged even when an excessive force is applied when the ball screw device is used at a high speed or when the rolling element is clogged, and the ball screw device is increased in speed and durability. be able to.

Moreover, since the stress relaxation part which relieve | moderates the stress added between a main body and a seat part is formed in the vicinity of the seat part of a main body and a reinforcement part, the stress concentration which arises between a main body and a seat part is prevented. It becomes possible.
In addition, as a circulation part, a leg part fitted in the circulation hole of the nut at both ends, and a passage of a rolling element in the leg part is formed to be inclined with respect to the outer peripheral surface of the leg part. By using it, it is possible to easily realize the scooping of the rolling element in the tangential direction and in the lead angle direction.

Hereinafter, an example of the first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view for explaining a ball screw device as an example of this embodiment, FIG. 2 is a right side view of FIG. 1, FIG. 3 is an overall perspective view of a presser, and FIG. FIG. 5A is a partial cross-sectional view showing a state before cutting the surplus portion, and FIG. 5B is a partial cross-sectional view showing a state after cutting the surplus portion. is there.

As shown in FIGS. 1 and 2, the ball screw device 20 as an example of this embodiment includes a screw shaft 22 having a spiral thread groove 21 on the outer peripheral surface and a spiral corresponding to the screw groove 21 on the inner peripheral surface. A nut 24 having a threaded screw groove 23 is screwed together, and the screw groove 23 of the nut 24 and the screw groove 21 of the screw shaft 22 face each other to form a spiral load region therebetween. .
A large number of balls 25 as rolling elements are slidably loaded in the load region, and the nut 24 (or screw shaft 22) rolls the balls 25 by the rotation of the screw shaft 22 (or nut 24). It moves in the axial direction.
A flat surface 24a is formed on a part of the side surface in the circumferential direction of the nut 24, and a synthetic resin circulation part 27 having an internal circulation path for the balls 25 is attached to the flat surface 24a. .

  The circulation component 27 includes a main body 31 and a pair of leg portions 30 such as a columnar shape or a block shape that are provided at both ends of the main body 31 and extend in a direction substantially perpendicular to the axial direction of the screw shaft 12. The pair of leg portions 30 are spaced apart from each other in the axial direction of the screw shaft 22 and spaced from each other in the radial direction of the screw shaft 22. These leg portions 30 are in communication with the load region between the screw grooves 21 and 23 and are fitted into a pair of elongated holes 34 formed in the flat surface 24 a of the nut 24. Yes. Further, the circulation path of the ball 25 inside each leg 30 is arranged so as to extend in a direction substantially tangential to the screw shaft 22 and in a direction substantially coincident with the lead angles of both screw grooves 21 and 23.

The circulating part 27 scoops up the ball 25 rolling in the load region between the screw grooves 21 and 23 from one leg portion 30 and guides it to the outside of the nut 24, and from the other leg portion 30 to the load region. A ball circulation path to return to is formed in the circulation component 27.
The circulating component 27 is different from the tube-type circulating component 8 used in the conventional ball screw device shown in FIG. 10 in that a pair of leg portions 30 are almost formed in the circulating hole 34 formed on the flat surface 24 a of the nut 24. The point is that the direction of the circulation path of the ball 25 formed inside the leg portion 30 can be inclined with respect to the outer peripheral surface of the leg portion 30 while being simply fitted without a gap.

For this reason, a circulating hole 34 is formed in the flat surface 24a of the nut 24 in a direction perpendicular to the screw shaft 22 as in the conventional ball screw device, and the circulating part 27 is simply formed in the circulating hole 34. While the leg portion 30 is fitted, the traveling direction of the ball 25 in the circulation path in the leg portion 30 is inclined in a direction substantially tangential to the screw shaft 22 and substantially coincident with the lead angles of both screw grooves 21 and 23. As a result, the processing of the nut 24 is simple, and the degree of freedom in design of the circulation path of the ball 25 in the circulation component 27 can be improved.
Here, in this embodiment, in a state where the leg portion 30 of the resin circulation part 27 is fitted in the circulation hole 34 of the nut 24, the circulation part 27 is attached to the nut 24 using the metal presser 40. It is fixed.

  As shown in FIG. 3, the presser 40 is formed by subjecting a metal plate material to a drawing process by a press machine, and substantially the entire portion exposed in the circumferential side surface of the nut 24 of the circulating component 27 (this example Then, a cap-shaped main body 41 that covers the entire area of the main body 31 of the circulating component 27 and a fixing seat 42 formed by folding back the opening end of the main body 41 on the nut 24 side on both sides in the width direction. And a reinforcing portion 43 formed by folding back the opening end of the main body 41 other than the seat portion 42 on the nut 24 side to the outside with a shorter length than the seat portion 42, and a screw insertion hole 44 in the seat portion 42. Is formed.

A corner R is formed between the main body 41 and the seat 42. This corner R is formed to be approximately R0.5 to R2.0.
As the metal material forming the presser 40, a stainless material having a tensile strength of 40 kgf / mm ² or more is used.
Here, the folding length of the reinforcing portion 43 is preferably 0.5 to 5 times the plate thickness, and the length in the circumferential direction of the opening end on the nut 24 side of the folding portion of the reinforcing portion 43 and the seat portion 42 is as follows. 90% or more of the entire circumference of the open end is preferable.

FIG. 4 shows an intermediate process when the presser 40 is formed.
When the presser 40 is formed, first, the shape of the main body 41 as shown in FIG. 4 is formed by deep drawing, and then the inside of the portion of the main body 41 that protrudes outward from the opening end side of the nut 24. The surplus portion 45 (see FIG. 5A) other than the seat portion 42 is cut from the side surface of the main body 41 at a position outside the predetermined dimension (see FIG. 5B), thereby forming the reinforcing portion 43.

  In addition, with reference to FIG. 3, the said reinforcement part 43 is not provided in the edge part 40a of the longitudinal direction of the pressing tool 40. As shown in FIG. This is because, as shown in FIG. 1, the presser 40 is fixed to the nut 24, so that if the reinforcing portion 43 is provided at the end portion 40a, the reinforcing portion 43 is prevented from interfering with the flange 24b of the nut 24. For this reason, the disadvantage that the length of the nut 24 becomes longer occurs. However, this end portion 40a is also a portion to which the push-up force from the circulating component 27 is not applied so much, and when the length of the nut 24 is shortened, the reinforcing portion 43 may not be provided. When there is a margin, it is preferable to provide the reinforcing portion 43 on the entire circumference.

Then, the main body 41 of the retainer 40 is fitted into the main body 31 of the circulating component 27, and in this state, the screw 29 inserted through the screw insertion hole 44 of the seat portion 42 is provided in the screw hole (see FIG. The circulating component 27 is fixed to the nut 24 by tightening to the nut 24.
Thus, in this embodiment, since the substantially entire area of the circulation component 27 is covered with the main body 41 of the metal presser 40, the balls 25 cause a circulation failure in the circulation component 27 and the circulation component 27 is placed inside. Even if pushed, the floating of the circulating component 27 can be prevented, and the sound transmitted from the inside of the circulating component 27 and released to the outside can be blocked to reduce the noise.

Further, since the seat portion 42 of the metal presser 40 is screwed and fixed to the nut 24, there is no concern that the screw tightening may be loosened due to creep deformation of the resin circulating component 27, and the circulating component. 27 can be reliably and easily fixed to the nut 24. Furthermore, since the presser 40 is formed by deep drawing of a metal plate, mass production is possible at low cost.
Further, the retainer 40 of the circulation component 27 includes a main body 41 covering the circulation component 27, a fixing seat 42 formed by folding an opening end of the main body 27 on the nut 24 side outward, and a nut of the main body 27. Since there is a reinforcing portion 43 formed by folding the opening end other than the seat portion 42 on the 24 side outward with a shorter length than the seat portion 42, the body 41 is particularly susceptible to vibration and damage. The thickness of the open end other than the seat portion 42 on the nut 24 side can be increased, and the strength of the entire presser 40 can be increased by the reinforcing portion 43 by folding.

In addition, since the corner R is formed between the main body 41 and the seat portion 42, the stress concentration generated between the main body 41 and the seat portion 42 is alleviated.
Further, since the stainless material having a tensile strength of 40 kgf / mm ² or more is used as the metal material forming the presser 40, it is possible to improve the durability of the presser 40 against repeated loads.

As a result, it is possible to prevent the presser 40 from being damaged even when an excessive force is applied when the ball screw device is used at high speed or when the rolling element is clogged, and the ball screw device can be increased in speed and improved in durability. Can be planned.
In addition, in this embodiment, it has the leg part 30 fitted to the circulation hole 34 of the nut 24 in both ends as resin-made circulation components, and the circulation path of the ball | bowl 25 in each leg part 30 is the leg part 30. However, the present invention is not limited to this example. For example, the presser of the tubular circulation component 8 of the ball screw device shown in FIG. May be applied.

In the present embodiment, a stainless material having a tensile strength of 40 kgf / mm ² or more is used as the metal material for forming the presser 40. However, the present invention is not necessarily limited thereto, and the metal for forming the presser 40 is For example, you may use press steel plates, such as SPCC and SPCE.
In addition, as described above, the presser 40 has many portions that have been subjected to deep drawing or the like, and has many altered layers resulting from this. For this reason, for example, durability against vibration applied by the operation of the ball screw device 20 may be improved by relaxing work hardening by shot peening or the like.

Hereinafter, an example of the second embodiment of the present invention will be described with reference to the drawings.
FIG. 6 is an overall perspective view of a presser provided in a ball screw device as an example of this embodiment, and FIG. 7 is an overall perspective view of a circulating component.
The presser 40 provided in the ball screw device as an example of the present embodiment is the same as that of the first embodiment described above except for the following points. That is, as shown in FIG. 6, a stress relaxation portion 46 that relaxes stress is formed at the boundary between the reinforcing portion 43 and the seat portion 42 of the presser 40.

The stress relieving part 46 is composed of a notch 47 that continues the boundary between the seat part 42 and the reinforcing part 43, and is formed on both ends of the seat part 42.
The presser 40 and the circulation component 27 are in contact with each other on a continuous surface including the central portion of the circulation component 27. As shown in FIG. 7, the contact surface between the presser 40 and the circulating component 27 has a length along the length direction of the circulating component 27 at the contact portion of the presser 40 with the circulating component 27 as CL. When the length of 27 is L and the width of the circulating component 27 is W, the conditional expression of L-3W ≦ CL ≦ LW is established.

  Thus, in this embodiment, since the stress relaxation part 46 which relieve | moderates the stress added between the main body 41 and the seat part 42 is formed in the vicinity of the seat part 42 of the main body 41 and the reinforcement part 43, the main body The stress concentrated between the bent portion 41 and the seat portion 42, that is, the bent portion having a low strength due to the structure is relieved, and the strength of the presser 40 can be improved. This is because, as shown in FIG. 8, when the ball screw device is used, a portion in which the traveling direction of the ball changes mainly in the circulating component 27 (in the drawing, indicated as “travel direction changing portion”), that is, circulation. As shown in FIG. 9, due to the lifting force generated in the vicinity of the leg portion of the component 27, the stress concentrated between the main body 41 and the seat portion 42 is caused by the moment force F applied to the presser 40 with the seat portion 42 as a fulcrum. This is because the lifting force can be relieved by the stress relieving portion 46 in the presser 40 of the present embodiment.

  In the present embodiment, the presser 40 and the circulation component 27 are in contact with each other on a continuous surface including the central portion of the circulation component 27. Further, the contact surface between the presser 40 and the circulating component 27 has a length along the length direction of the circulating component 27 at a contact portion of the presser 40 with the circulating component 27 as CL, and the length of the circulating component 27 is set to be the length of the circulating component 27. When L is L and the width of the circulating component 27 is W, the conditional expression of L-3W ≦ CL ≦ LW is established. For this reason, since it becomes possible to prevent the repetitive stress applied to the presser 40 by the circulating component 27, that is, the lifting force generated in the vicinity of the leg portion of the circulating component 27, from being applied to the end portion of the main body 41. The stress concentrated between the seat 41 and the seat 42 is relaxed, and the strength of the presser 40 can be improved. This is because the lifting force generated in the vicinity of the leg portion of the circulating component 27 is applied to the central portion of the main body 41 and the vicinity thereof.

As a result, when excessive force is applied due to high speed use of the ball screw device, clogging of rolling elements, etc., or when a large diameter ball is used, especially when the frequency and thrust force are large, It is possible to prevent cracks and the like from occurring at the nut-side opening end in the vicinity of the seat portion 52 of the main body 51. As a result, it is possible to prevent the presser 40 from being damaged, and to increase the speed and durability of the ball screw device.
In this embodiment, the stress relaxation part 46 is formed by the notch 47 in which the main body 41 and the reinforcing part 43 are continuous. However, the present invention is not limited to this, and the stress relaxation part 46 is, for example, the main body 41. The reinforcing portion 43 may be formed by a continuous slit.

It is explanatory drawing for demonstrating the ball screw apparatus which is an example of 1st embodiment of this invention. It is a right view of FIG. It is a whole perspective view of a pressing tool. It is a perspective view which shows the shape of the middle process at the time of shape | molding a pressing tool. (A) is a fragmentary sectional view which shows the state before the cutting of a surplus part, (b) is a fragmentary sectional view which shows the state after the cutting of a surplus part. It is a whole perspective view of the presser provided in the ball screw device which is an example of the second embodiment of the present invention. It is a whole perspective view of a circulation component. It is a figure which shows the passage route of the ball | bowl in a circulation component. It is a figure which shows the force added to a holding tool. It is principal part sectional drawing for demonstrating the conventional ball screw apparatus. It is a figure which shows the state which attached the conventional presser to the circulation tube. It is a figure which shows the conventional presser. It is the figure seen from the arrow A direction of FIG. It is the figure seen from the arrow B direction of FIG. It is a disassembled perspective view which shows an example of the conventional circulation component. It is a whole perspective view of a pressing tool. (A) is a fragmentary sectional view which shows the state before the cutting of a surplus part, (b) is a fragmentary sectional view which shows the state after the cutting of a surplus part.

Explanation of symbols

20 Ball screw device 21 Screw groove 22 Screw shaft 23 Screw groove 24 Nut 25 Ball (Rolling element)
27 Circulating parts 30 Legs 34 Circulating holes 40 Presser 41 Main body 42 Seat part 43 Reinforcement part 46 Stress relaxation part 47 Notch

Claims (9)

A set of two circulation holes provided on the side surface of the nut for rolling elements that roll in a load region between a screw groove of a screw shaft of a ball screw device and a screw groove of a nut screwed to the screw shaft A circulating part having both ends fitted to each circulation hole so as to form a rolling element circulation path that leads from one circulation hole to the outside of the nut and returns to the load region from the other circulation hole. A presser for fixing,
A main body that is formed by deep drawing and covers the circulating component, a fixing seat formed by folding the nut-side opening end of the main body outward, and the seat on the nut side of the main body And a reinforcing part formed by folding the open end of the outer part outward with a shorter length than the seat part.   2. The circulating component presser according to claim 1, wherein a folding length of the reinforcing portion is 0.5 to 5 times a plate thickness of a portion excluding the seat portion.   The length in the circumferential direction of the opening end on the nut side of the folded portion of the reinforcing portion and the seat portion is set to 90% or more of the entire circumference of the opening end. Retaining part for circulating parts.   The stress relaxation part which relieve | moderates the stress added between the said main body and the said seat part in the vicinity of the said seat part of the said main body and the said reinforcement part was formed. Cycling part presser described in 1.   The circulating part presser according to claim 4, wherein the stress relaxation part is configured by a notch that is continuous at a boundary between the seat part and the reinforcing part. The presser for a circulating component according to any one of claims 1 to 5, wherein the presser is made of a stainless material having a tensile strength of 40 kgf / mm ² or more. The presser is in contact with the circulating component on a continuous surface including the central portion of the circulating component,
When the length along the length direction of the circulating component at the contact portion of the presser with the circulating component is CL, the length of the circulating component is L, and the width of the circulating component is W, L The circulating part presser according to any one of claims 1 to 6, wherein a conditional expression of -3W≤CL≤LW is satisfied. A screw shaft having a spiral thread groove on the outer peripheral surface, a nut having a spiral thread groove corresponding to the screw groove of the screw shaft on the inner peripheral surface and screwed onto the screw shaft, and the both screws A large number of rolling elements loaded in a load area between the grooves so as to be able to roll, and the rolling elements that roll in the load area are arranged in one of a pair of circulation holes provided on the side surface of the nut. Circulating parts having both ends fitted to the respective circulation holes to form inside a rolling element circulation path that leads from the circulation hole to the outside of the nut and returns from the other circulation hole to the load region; and In a ball screw device having a presser to be fixed,
A ball screw device using the presser according to any one of claims 1 to 7 as the presser.   The circulating component has leg portions fitted to the circulation holes of the nut at both ends, and the passage of the rolling element in the leg portion is formed to be inclined with respect to the outer peripheral surface of the leg portion. 9. The ball screw device according to claim 8, wherein the ball screw device is provided.

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