KR102291546B1 - nut - Google Patents

Abstract

The laminated nut 10 has a plurality of thin-shaped nuts 12 in which through-holes 16 of substantially the same diameter are formed. On the inner peripheral surface of each thin nut 12 , a plurality of threads 18 , 38 are formed to protrude inward of the through hole 16 at predetermined angular intervals. In this case, each thin nut 12 is laminated along the direction of the central axis 14 so that each through hole 16 is approximately coaxial, and a laser is applied to the outer peripheral surface of each thin nut 12 in the laminated state. Each thin nut 12 is joined by welding etc., and the lamination|stacking nut 10 is completed.

Description

nut

The present invention relates to a nut used for a feed screw nut of an electric actuator.

For example, as shown in FIG. 7 , in the electric actuator 50 for conveying a workpiece, when the feed screw shaft 52 is rotationally driven by a motor (not shown), the screw is screwed to the feed screw shaft 52 . The coupled feed screw nut 54 slides in the axial direction of the feed screw shaft 52 under the rotational action of the feed screw shaft 52 . In addition, since the structure of the electric actuator 50 is well-known, the detailed description is abbreviate|omitted.

By the way, the threading with respect to the feed screw nut 54 is performed by the cutting process with a tap or a threading bite, for example. In addition, Japanese Unexamined Patent Application, First Publication No. 6-81828, Japanese Unexamined Patent Publication No. 7-224826, Japanese Unexamined Patent Application, First Publication No. Hei 9-242841, Japanese Unexamined Patent Publication No. 9-317741, Japanese Unexamined Patent Publication No. 11-82459, Japanese Unexamined Patent Publication No. 2006 -346704 and Japanese Utility Model Registration No. 3100223 disclose a conventional nut manufacturing method including cutting.

However, as shown in Figs. 7 and 8, in the conventional feed screw nut 54, since the entire nut is manufactured as a single component, it becomes an individual component for each specification such as screw length, and there is no need for individual management. have.

Moreover, since it manufactures using cutting tools, such as a tap and a thread cutting bite, the screw length of the feed screw nut 54 is restrict|limited by the length of a cutting tool. Furthermore, when surface treatment for forming a protective film on the screw portion 56 of the feed screw nut 54 is performed for the purpose of reducing wear and improving sliding performance, the thickness control of the protective film in the central portion of the screw portion 56 is difficult

Further, in proportion to the amount of cutting of the workpiece to be the feed screw nut 54 , the manufacturing cost of the feed screw nut 54 increases. For example, in the case of forming the thread portion 56 of a multi-thread screw, especially in cutting using a threading bite, it is necessary to reciprocate the cutting tool by the number of threads of the screw with respect to the workpiece. This is required, and the manufacturing cost increases.

The present invention has been made to solve the above problem, and an object of the present invention is to provide a nut that can be easily managed and manufactured at low cost by reducing processing time.

In order to achieve the above object, a nut according to the present invention has a plurality of plate-shaped members having through-holes of approximately the same diameter formed therein, and each of the plate-shaped members has a plurality of threads at predetermined angular intervals of the through-holes. Each of the plate-shaped members is stacked so as to protrude inwardly, and so that each of the through-holes is substantially coaxial.

According to this structure, the nut is comprised by laminating|stacking each said plate-shaped member in which the said screw thread was formed to protrude inward of the said through-hole. Therefore, in the present invention, since the cutting process is unnecessary, the machining time can be reduced and the manufacturing cost can be reduced.

To explain the above effect in more detail, instead of the conventional method in which the screw length is determined by the feed amount of cutting, in the present invention, the nut can be easily formed by stacking the plate-shaped members by the required screw length. can be assembled Thereby, with one type of the said plate-shaped member, the said nut which has various screw lengths as needed can be obtained. Further, the plate-like member is produced by forming the through hole and each of the threads by plastic deformation by press working or the like.

Further, in the present invention, since the screw length is not limited by the length of the cutting tool, the nut can be manufactured by stacking the plate-shaped members as many as necessary. Furthermore, since the protective film can be formed for each plate-like member, the thickness management of the protective film becomes easy.

According to the above configuration, in the present invention, the management of the nut is facilitated, the machining time is reduced, and the nut can be manufactured at low cost.

Here, in the present invention, each of the threads is a multi-thread thread, and between the threads of each of the plate-shaped members, each of the threads is along the axial direction of the nut. It is preferable that the clearance gap is formed so that these may not overlap with each other. Thereby, the said thread can be formed by plastically deforming the to-be-processed object which will become the said plate-shaped member.

In this case, if the thickness of each of the plate-shaped members is equal to or less than the screw pitch of each of the threads, the threads can be easily formed.

Further, in the present invention, by joining each of the plate-shaped members, the nut having a sufficient screw length to function as a feed screw nut can be easily obtained.

Specifically, in a state in which each plate-shaped member is stacked so that the threads of each of the plate-shaped members are connected along the axial direction of the nut, the outer peripheral portion of each of the plate-shaped members is preferably joined.

Further, by joining each of the plate-like members in a state in which a jig having an external screw is screwed to each of the threads, the nut can be manufactured while controlling the screw pitch with sufficient precision.

In this case, it is preferable that each of the plate-shaped members is laminated without a gap along the axial direction with respect to the jig by screwing each of the screw threads to the male screw. Thereby, the said nut can be manufactured with high precision in the state without backlash.

In order to adjust the backlash formed between the nut and the screw shaft when the nut is screwed to the screw shaft of the object to a predetermined backlash according to the specifications of the object, each of the plate-shaped members is , it is preferable that each of the threads is screwed to the male thread of any one of the plurality of jigs, so that the single jig is laminated without a gap. Even in this case, the nut can be manufactured with high precision without backlash. Further, an appropriate jig is selected according to the specification of the object when the nut is screwed to the screw shaft of the object (for example, the specification of an electric actuator assembled as a feed screw nut), and the selected male screw of the jig is A nut may be manufactured by screwing each of the plate-shaped members to the nut. In this way, when the manufactured nut is screwed to the screw shaft of the object (the feed screw shaft of the electric actuator), the backlash formed between the nut and the screw shaft is reduced to a predetermined backlash according to the specification ( For example, it becomes possible to adjust to the optimal backlash).

And, by joining each of the plate-shaped members by welding, the above-described nut can be easily obtained.

1 is a perspective view showing the assembly of a laminated nut according to the present embodiment.
FIG. 2A is a front view of the thin nut of FIG. 1 , and FIG. 2B is a cross-sectional view taken along line IIB-IIB of FIG. 2A .
3 is a cross-sectional view showing the formation of a threaded portion of the thin nut.
4A is a perspective view illustrating a case in which a laminated nut is manufactured using a pitch management jig, and FIG. 4B is a cross-sectional view taken along line IVB-IVB of FIG. 4A.
5A is a perspective view illustrating another configuration of the stacked nut, and FIG. 5B is a cross-sectional view taken along the line VB-VB of FIG. 5A.
6A is a cross-sectional view illustrating a case in which the laminated nut is manufactured in a state without backlash using a pitch management jig, and FIG. 6B is a case in which the laminated nut manufactured by the method of FIG. 6A is screwed to the feed screw shaft. It is one cross section.
7 is a partial cross-sectional view of the electric actuator.
8 is a perspective view of the feed screw nut of FIG. 7 .

A preferred embodiment of the nut according to the present invention will be described in detail below with reference to the drawings.

[Configuration of this embodiment]

As shown in FIGS. 1 to 3 , the nut 10 according to the present embodiment includes a plate-shaped member 12 of substantially the same shape made of metal such as aluminum in a direction along a central axis 14 (axial line). direction), and joining the outer periphery of each plate-shaped member 12 after lamination by a welding process such as laser welding. In addition, in the following description, the plate-shaped member 12 relatively thin compared to the nut 10 is referred to as a thin nut 12, and a nut 10 constituted by stacking a plurality of thin nut 12 is provided. It is also called the lamination nut 10 in some cases.

The thin nut 12 is a washer-shaped (ring-shaped) thin member in which the through hole 16 is formed. On the inner peripheral surface of the thin nut 12 , a plurality of threads 18 are formed to protrude inward of the through hole 16 at predetermined angular intervals. In addition, in FIGS. 1-3, the case where the four thread|threads 18 are formed at intervals of about 90 degree|times as an example is shown.

Each thread 18 is a multi-thread thread. Moreover, the clearance gap 20 is formed between each screw thread 18 formed at predetermined angular intervals. In this case, as shown in the cross-sectional view of FIG. 2B , in each thin nut 12 , in the direction along the central axis 14 , the respective gaps 20 are formed so that the respective threads 18 do not overlap each other. is formed

In addition, in this embodiment, each thin nut 12 is installed in a state in which the phase of each thread 18 is shifted so that each thread 18 is continuous (connected) between adjacent thin nut 12. By overlapping in the direction of the central axis 14, each thin nut 12 is laminated|stacked. In this case, the thickness L of the thin nut 12 is set to be equal to or less than the thread pitch P of the threaded portion 22 (each thread 18 of) constituted by laminating each thin nut 12 . . In addition, in this embodiment, the case where the number of pairs is 4 and L = P/2 (half pitch) is shown as an example.

Then, as shown in FIG. 3 , by applying a compressive force to the plate-shaped workpiece 24 by press working or the like from the left and right directions along the central axis 14, the through-hole 16 ) and the thread 18 are formed, so that the thin nut 12 is manufactured. In FIG. 3 , a state in which a compressive force is applied is shown by a dotted arrow.

4A and 4B show a case in which the multilayer nut 10 is assembled, and the feed screw nut 26 for the electric actuator 50 (refer to FIG. 7) as an object is manufactured.

First, similarly to the feed screw shaft 52 , each thin nut 12 is screwed to the cylindrical pitch management jig 28 in which the male screw 27 is formed. In this case, each thin nut 12 is screwed to the male screw 27 of the jig 28 for pitch management one by one, and each thin nut 12 is brought into close contact with the adjacent thin nut 12 . It can be set as a laminated state.

Next, one end side of the jig 28 for pitch management is inserted into the through hole 32 of the cylindrical member 30, and the cylindrical member 30 abuts on one surface of the laminated body of each thin nut 12. let it be Moreover, the other end side of the jig 28 for pitch management is inserted into the through-hole 36 of the block 34, and the block 34 is made to contact|abut against the other surface of the laminated body of each thin-shaped nut 12. As shown in FIG.

Next, as shown by the dotted arrow, each thin nut 12 is joined by performing welding processing such as laser welding in the circumferential direction on the outer peripheral portion of the laminate of each thin nut 12 . Thus, the laminated nut 10 is manufactured. Further, by joining the contact point between the lamination nut 10 and the cylindrical member 30 by laser welding or the like, and by joining the contact point between the lamination nut 10 and the block 34 by laser welding or the like. Complete the feed screw nut (26). In addition, the welding process with respect to the outer peripheral part of a laminated body is performed at the some location along the circumferential direction, for example.

As a result, the feed screw nut 26 including the lamination nut 10 according to the present embodiment is replaced with the conventional feed screw nut 54 (refer to FIGS. 7 and 8) to the electric actuator 50. It becomes possible to mount In addition, in the above description, although the case where the pitch management jig 28 of a member separate from the feed screw shaft 52 was used has been described, the feed screw shaft 52 itself is a pitch management jig 28 . may be

[Modification of this embodiment]

5A and 5B show a modified example of the lamination nut 10 according to the present embodiment. 5A and 5B, only one thin nut 12 and the pitch management jig 28 (or the feed screw shaft 52) are shown for ease of explanation.

This modified example shows the case where the round screw thread 38 is constituted by forming hemispherical projections at predetermined angular intervals on the inner circumferential surface of the thin nut 12 . Even in this case, if each thin-shaped nut 12 is laminated in the direction of the central axis 14 and laser welding is performed on the outer peripheral surface of each thin-shaped nut 12, it is composed of a round screw thread 38 A laminated nut 10 having a threaded portion 22 can be manufactured.

Thus, in this embodiment, the shape of the threads 18 and 38 is capable of screwing the lamination nut 10 with respect to the feed screw shaft 52 used in combination with the lamination nut 10 . Any shape is employable. That is, the function of the lamination|stacking nut 10 can be achieved even if it employ|adopts the thread of a trapezoid shape and a triangular shape other than the shape of a general metric screw (standard screw), for example.

6A and 6B show another modified example of the lamination nut 10 according to the present embodiment. In addition, for ease of explanation, only two thin nuts 12 and a pitch management jig 28 are shown in FIG. 6A , and two thin nuts 12 and a feed screw shaft 52 in FIG. 6B . only shows

As shown in FIG. 6A , the thin nut 12 having threads 18 and 38 is screwed to the male thread 27 of the jig 28 for pitch management. In this case, the thin nut 12 is screwed into the male screw 27 one by one. Thereby, each thin nut 12 is laminated|stacked without a gap in the direction along the central axis 14, and the laminated nut 10 is comprised. At that time, since an axial force is generated between each thin nut 12, each thin nut 12 is stacked without a gap while being inserted like a double nut. With each thin nut 12 in such a laminated state, the laminated nut 10 is manufactured with high precision in a state without backlash. In addition, it goes without saying that the above-mentioned welding process is performed also in the lamination nut 10 .

And, as shown in Fig. 6b, the lamination nut 10 manufactured by the method of Fig. 6a is, for example, a feed screw shaft of a triangular screw having a smaller diameter than the male screw 27 of the jig 28 for pitch management. Screw into (52). In this case, since the diameter of the feed screw shaft 52 is smaller than the diameter of the screw portion 22 of the lamination nut 10 , the central shaft 14 is disposed between the screw portion 22 and the feed screw shaft 52 . Backlash (b) of the gap width parallel to . As described above, since the lamination nut 10 is manufactured with good precision in the absence of backlash, by combining the lamination nut 10 and the feed screw shaft 52, the backlash b can be made to a desired size. .

Moreover, in another modification, the several jigs 28 for pitch management from which the diameter (for example, effective diameter) of the external screw 27 differ can also be prepared in advance. In this case, according to the specifications of the electric actuator 50 having the feed screw shaft 52, any one of the pitch management jigs 28 is selected, and each of the male threads 27 of the selected pitch management jig 28 is attached. Screw the thin nut 12 of Even in this case, an axial force is generated between each thin nut 12, and each thin nut 12 is stacked without a gap in a screwed state like a double nut. As a result, the lamination nut 10 is manufactured with good precision in a state without backlash.

After that, when the stacked nut 10 is screwed to the feed screw shaft 52 , the backlash b formed between the feed screw shaft 52 and the stacked nut 10 is the specification of the electric actuator 50 . It becomes the optimal backlash according to That is, in another modified example, it is possible to adjust the magnitude|size of the backlash b step by step by preparing the plurality of pitch management jigs 28 whose diameters were changed step by step. As a result, in the case where the accuracy of the feed screw shaft 52 is allowed to decrease to some extent due to mass productivity or cost aspects, the optimal lamination nut 10 according to the specification is manufactured with good precision, so the backlash ( b) is easier to adjust. That is, in another modified example, the backlash b can be adjusted to the optimal backlash according to the specification of the electric actuator 50. As shown in FIG.

In addition, in this embodiment, the welding process with respect to the outer peripheral part of each plate-shaped member 12 in a laminated state is not limited to the above-mentioned laser welding. It goes without saying that the laminated nut 10 can be manufactured by performing another welding process such as resistance welding.

In addition, in this embodiment, bonding of each plate-shaped member 12 in a laminated state is not limited to various welding, such as laser welding mentioned above. It is also possible to produce the lamination nut 10 by bonding each plate-shaped member 12 in a laminated state by another bonding method such as an adhesive or a rivet.

[Effect of this embodiment]

As described above, according to the lamination nut 10 according to the present embodiment, each thin nut 12 in which each screw thread 18 , 38 is formed to protrude to the inside of the through hole 16 is laminated by laminating. A nut 10 is constructed. Therefore, in this embodiment, since a cutting process is unnecessary, machining time can be saved, and manufacturing cost can be reduced.

If this effect is described in more detail, instead of the conventional method in which the screw length is determined by the feed amount of cutting, in this embodiment, the laminated nut 10 is stacked by the required screw length by laminating the thin nut 12 can be easily assembled. Thereby, with one type of thin nut 12, the lamination|stacking nut 10 which has various screw lengths as needed can be obtained.

Moreover, in this embodiment, since the screw length is not restrict|limited by the length of a cutting tool, the thin-shaped nut 12 can be laminated|stacked by a required number, and the lamination|stacking nut 10 can be produced. Moreover, since a protective film can be formed for each thin nut 12, thickness management of the protective film becomes easy.

With the above configuration, with the laminated nut 10 according to the present embodiment, the management of the laminated nut 10 is facilitated, the machining time is reduced, and the laminated nut 10 can be manufactured at low cost.

Moreover, in the lamination nut 10, each thread 18, 38 is a multi-thread thread, and between each thread 18, 38 in each thin nut 12, the lamination nut 10 ), a gap 20 is formed so that the respective threads 18 and 38 do not overlap each other in the direction along the central axis 14 . Thereby, the thread 18 can be formed by plastically deforming the to-be-processed object 24 which will become the thin nut 12. As shown in FIG.

In this case, if the thickness L of each thin nut 12 is equal to or less than the thread pitch P of each thread 18, 38, each thread 18, 38 can be easily formed.

Moreover, in this embodiment, by joining each thin-shaped nut 12 in a laminated state, the laminated nut 10 which has a sufficient screw length in order to function as the feed screw nut 26 can be obtained easily.

Specifically, in a state in which each thin nut 12 is stacked so that each thread 18 , 38 is connected in a direction along the central axis 14 of the laminated nut 10 , the The outer peripheral part is joined.

In this case, in a state in which the pitch management jig 28 (or the feed screw shaft 52) having the male screw 27 formed thereon is screwed to each of the threads 18 and 38, each thin nut 12 is joined. By doing so, the laminated nut 10 can be manufactured while the screw pitch P is managed with sufficient precision.

Moreover, by screwing the threads 18 and 38 of each thin nut 12 to the male thread 27 of the jig 28 for pitch management, each thin nut 12 is the jig 28 for pitch management. ), since they are laminated without a gap along the central axis 14 , the lamination nut 10 can be manufactured with high precision in a state without backlash.

Furthermore, when the stacked nut 10 is screwed to the feed screw shaft 52 of the electric actuator 50, the backlash (b) formed between the stacked nut 10 and the feed screw shaft 52 is transmitted In order to adjust to a predetermined backlash b according to the specifications of the actuator 50, each thin nut ( By screwing the threads 18 and 38 of 12), each thin nut 12 is laminated without a gap with respect to the one pitch management jig 28. Also in this case, the lamination nut 10 can be manufactured with high precision in a state without backlash. In addition, according to the specification of the electric actuator 50 to which the lamination nut 10 is assembled as a feed screw nut, an appropriate pitch management jig 28 is selected, and the male screw 27 of the selected pitch management jig 28 is attached. By screwing each thin nut 12, the laminated nut 10 can be manufactured. When the stacked nut 10 produced by this is screwed onto the feed screw shaft 52 of the electric actuator 50, the backlash formed between the stacked nut 10 and the feed screw shaft 52 ( b), it becomes possible to adjust the optimum backlash according to the specification.

And when the outer peripheral portions of each plate-shaped member 12 in the laminated state are joined by welding, the above-described laminated nut 10 can be easily obtained.

In addition, this invention is not limited to embodiment mentioned above, It goes without saying that various structures can be employ|adopted without deviating from the summary of this invention.

Claims (9)

In the nut (10) having a plurality of plate-shaped members (12) in which the through-holes (16) of the same diameter are formed,
Each of the plate-shaped members 12, a plurality of threads (18, 38) at predetermined angular intervals are formed to protrude inward of the through hole (16),
Each of the plate-shaped members 12 is stacked so that each of the through-holes 16 is coaxial,
Backlash (b) formed between the nut 10 and the screw shaft 52 when the nut 10 is screwed to the screw shaft 52 of the object 50, the object 50 In order to adjust to a predetermined backlash (b) according to the specification of the male screw 27, each of the threads 18 and 38 on the male screw 27 of any one of the plurality of jigs 28 is formed. Nuts (10) characterized in that by this screwing, each of the plate-shaped members (12) is laminated with respect to one of the jigs (28) along the axial direction of the nut (10) without a gap. ). The method according to claim 1,
each said thread (18, 38) is a thread of a multi-thread thread;
Between each of the threads 18 and 38 in each of the plate-shaped members 12, there is a gap along the axial direction of the nut 10 so that the threads 18, 38 do not overlap each other. Nut (10), characterized in that (20) is formed. The method according to claim 1,
A nut (10), characterized in that the thickness (L) of each of said plate-shaped members (12) is equal to or less than the thread pitch (P) of each of said threads (18, 38). The method according to claim 1,
Nuts (10), characterized in that each of the plate-shaped members (12) is joined. 5. The method according to claim 4,
In a state where each of the plate-shaped members 12 is stacked so that the threads 18 and 38 of each of the plate-shaped members 12 are connected along the axial direction, the outer periphery of each of the plate-shaped members 12 is Nut (10), characterized in that the parts are joined. 5. The method according to claim 4,
A nut (10) characterized in that each of the plate-shaped members (12) is joined in a state in which the jig (28) is screwed to each of the threads (18, 38). delete delete 5. The method according to claim 4,
A nut (10) characterized in that each of the plate-shaped members (12) is joined by welding.

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