KR101277383B1 - Form rolling die - Google Patents

Abstract

Provides an extremely practical roll die that can minimize the interference between the rolled member and the rolled tooth of the die to prevent scratches or burrs on the tooth surface of the rolled member.
A rolling die for rolling a desired tooth by plastically deforming the outer circumferential surface by contacting the rolling tooth 2 with the outer circumferential surface of the to-be-rolled member 1, wherein at least one end of each of the teeth 3 This thickness (T) is formed thinner than the central portion at a predetermined height position to form an interference mitigating portion (R) for mitigating interference with the member (1).

Description

Rolling Dies {FORM ROLLING DIE}

The present invention relates to a roll die.

Conventionally, a rolling flat die (bitting section) for plasticizing a tooth (threaded thread) of a worm or a screw by applying pressure while inserting and rotating a roughly cylindrical member to be rolled (work). A biting portion, a finishing portion, and a relief portion are formed in succession) and other rolling dice have been proposed (see Patent Document 1, for example).

By the way, since the tooth surface roughness of a rolled product affects the operation sound, the lifetime, power consumption, etc. by abrasion of a counterpart component, it is preferable that it is small (smooth) as possible as possible. In general, a so-called incomplete screw (teeth) portion having different teeth and pitches and a portion where a regular tooth (threaded thread) is formed are present at the boundary portion between the worm portion and the screw portion and the substantially cylindrical portion where they are not formed. In this part as well, the roughness is preferably as small (smooth) as possible. However, it does not become smooth, and a wound, a burr, etc. may arise at the time of a rolling process.

For example, in the case of the so-called finish rolling in which the finishing processing is performed on a pre-worked workpiece in which teeth are formed to some extent by preliminary processing such as screw cutting or rough rolling, the amount of crushing is usually The amount of advancing) is about several micrometers for the purpose of obtaining the burnishing effect (smooth the surface). However, the edges of the chamfers formed at the side ends of the die (edge edges) formed by the axial movement of the workpiece during the rolling and the mechanical stiffness are affected by the work. A wound may occur at the tooth surface at the end of the work piece.

In addition, in the case of so-called solid rolling, which forms teeth directly on solid workpieces which are not subjected to the preliminary machining, axial stretching occurs at both ends of the workpiece due to machining at the biting portion, and during rolling. At one end, it does not interfere with the rolling teeth of the die. Thereafter, the end portion of the work is fitted into the die again at the finish portion due to the progression. However, since the pitch and the tooth thickness do not correspond to the rolling teeth of the die at the end portion where the elongation has occurred, it may be burned out and a deviation may occur.

[Patent Document 1] Japanese Unexamined Patent Publication No. Hei 10-113740

The present invention solves the above problems, and it is extremely practical that the interference between the rolled member and the rolled tooth of the die can be suppressed as much as possible to prevent the occurrence of scratches or burrs on the tooth surface of the rolled member. It is to provide excellent rolling dice.

The gist of the present invention will be described with reference to the accompanying drawings.

A rolling die for rolling a tooth of a worm or a screw by plastic deformation of the outer circumferential surface by bringing a rolling tooth into contact with an outer circumferential surface of a member to be rolled, wherein at least one end of the rolling tooth is formed at each tooth. An interference mitigating portion is formed so as to be thinner than the central portion at a predetermined height position to mitigate interference with the to-be-rolled member, and the interference mitigating portion is a tooth groove between each tooth of the rolling tooth shape. The inclined angle of the bottom end of the rolling tooth shape is inclined downward at a predetermined angle toward the outside, and the inclination angle of the bottom end portion of the rolling tooth is the same as that of the rolling die. It is set at an angle greater than 0 degrees and within 60 degrees with respect to a reference plane or a straight line parallel to the reference line, and each tooth of at least one side end of the rolling tooth shape is the front teeth. It relates to a rolling die characterized in that the chamfer is greater than 20 ° and chamfered within 60 ° with respect to the reference plane or the straight line parallel to the reference line.

delete

delete

delete

delete

In the rolling die according to claim 1, the inclination angle of the side end portion 8 of the bottom 6 is the same angle as the chamfer angle or larger than the chamfer angle, and the reference plane or reference line of the rolling die. It relates to a rolling dice, characterized in that it is set at an angle within 60 ° to a straight line parallel to the.

delete

delete

delete

Further, a rolling die for rolling the outer circumferential surface by rolling the outer circumferential surface by contacting the rolling teeth 2 with the outer peripheral surface of the rolled member 1 to roll the teeth of a worm or screw, each of which is provided on at least one end of the rolling teeth 2. An interference mitigating portion R is formed in which the tooth thickness T of the tooth portion 3 is thinner than the central portion at a predetermined height position to mitigate interference with the to-be-rolled member 1, and this interference mitigating portion ( R) shows the shape of the tooth groove 5 between the teeth at the side end of the rolling tooth 2 in a cross section perpendicular to the rolling direction, so that the shape of the tooth groove 5 in the center portion is orthogonal to this rolling direction. And teeth 3 of at least one end of the rolling teeth 2, each having a shape parallel to the reference plane or reference line of the rolling die. Chamfer Greater than 60 ° and Within 60 ° Relates to a die precursor, it characterized in that it is chamfered to.

In the rolling die according to any one of claims 1 to 3, the rolling die is a biting portion (A), a finishing portion (B), and a relief portion (C) in order from the rolling direction start end side. Is a flat dice X formed continuously, and the interference mitigating portion R is at least formed in the finishing portion B and the relief portion C.

In the rolling die according to any one of claims 1 to 3, the rolling die is a round die (Y), and the interference mitigation portion (R) is formed over the entire circumference of the round die (Y). It relates to a rolling dice characterized in that.

In the rolling die according to any one of claims 1 to 3, the rolling die has a biting portion A, a finishing portion B, and a relief portion C successively from the rolling direction start side. It is a vacancy dice | dies Q formed, and the said interference alleviation part R is related with the rolling die which is formed in the said finishing part B and the relief part C at least.

Moreover, in the rolling die of Claim 4, the said interference alleviation part R relates to the rolling die which is formed in the both sides edge part of the said rolling tooth mold | type 2, respectively.

Moreover, in the rolling die of Claim 5, the said interference alleviation part R relates to the rolling die which is formed in the both sides edge part of the said rolling tooth mold | type 2, respectively.

Moreover, in the rolling die of Claim 6, the said interference alleviation part R is provided in the rolling die which is provided in the both ends of the said rolling tooth mold | type 2, respectively.

delete

delete

delete

Since the present invention is configured as described above, the roll die having extremely practicality can be suppressed as much as possible to prevent interference between the rolled member and the rolled tooth of the die and to prevent scratches or burrs on the tooth surface of the rolled member. Becomes

1 is a schematic explanatory perspective view of a flat dice.
2 is a schematic explanatory diagram of a rolling process using flat dice.
3 is a schematic view illustrating the configuration of the present embodiment.
4 is an enlarged schematic explanatory cross-sectional view of the main part of the present embodiment.
5 is an enlarged schematic explanatory view of the chamfer portion of the present embodiment.
6 is an enlarged schematic explanatory view of a chamfer of a conventional example.
7 is a schematic view illustrating the structure of a conventional example.
8 is an enlarged schematic explanatory cross sectional view of a main part of Exemplary Example 1 of the present embodiment.
Fig. 9 is a photograph illustrating a state of a wound (a) of a tooth surface of a to-be-rolled member and a defect of a tooth (b) at a side end portion of a rolling tooth mold generated when finishing rolling in the prior art.
Fig. 10 is a photograph illustrating a burr (a) produced when rolling in the air in the prior art, and the member to be b (b) with the burr suppressed in this embodiment.
11 is a schematic explanatory diagram of rolling processing using a round die according to Exemplary Example 2 of the present embodiment.
12 is a schematic explanatory diagram of rolling processing using a vacancy die according to another example 3 of the present embodiment.
It is a schematic diagram explaining the displacement measurement of a worm shaft.

EMBODIMENT OF THE INVENTION Embodiment of this invention which thinks it is suitable is demonstrated based on drawing of the action of this invention based on drawing.

When the rolled member 1 is sandwiched by a pair of rolled dice and rolled, the rolled tooth 2 is formed with the teeth 3 of the side end portions having a thin tooth thickness T and the rolled member 1. A gap G is formed between the engagement portion of the tooth 3 and the side end portion of the rolled tooth 2 and the interference between the rolled member 1. Therefore, in the case of finishing rolling, it is possible to prevent a wound on the tooth surface of the to-be-rolled member 1, and in the case of a solid rolling, it is possible to prevent burring at the end of the to-be-rolled member 1, The shift of the to-be-rolled member 1 can also be suppressed further.

[Example]

EMBODIMENT OF THE INVENTION The specific Example of this invention is described based on drawing.

This embodiment is a rolling die for rolling a desired tooth by plastically deforming the outer circumferential surface by contacting the rolling tooth 2 with the outer circumferential surface of the to-be-rolled member 1, each of which is provided at at least one end of the rolling tooth 2. An interference mitigating portion R is formed in which the tooth thickness T of the tooth portion 3 is thinner than the central portion at a predetermined height position to mitigate interference with the to-be-rolled member 1.

Here, the above-mentioned 'side end' or 'center part' indicates a position in a direction orthogonal to the rolling direction (rotational direction of the member to be rolled), and the same also applies to the following. Usually, since the rolling direction is often longer than the direction perpendicular to the rolling direction, the rolling direction may be referred to as the longitudinal direction.)

This embodiment is a flat dice X as shown in FIG. 1, and as shown in FIG. 2, a pair of flat dice X are arranged to face each other at predetermined intervals with respect to the target member 1. The tooth member F (threaded) of the worm or the screw is formed by inserting the member 1 between the surfaces and applying pressure while rotating. On the other hand, in Fig. 2, the die on the right side is fixed, and the left dice are moved to perform rolling, but it goes without saying that each die may move relative to each other in the opposite direction.

Specifically, as for the flat dice X, the bottom surface 9 in which the rolling teeth 2 are not formed is set as a dice reference surface, and a plurality of sets are formed on the upper surface on the opposite side to this bottom surface 9. The teeth 3 are rolled in a meandering state with respect to the rolling direction at predetermined intervals, and the rolling teeth 2 of the flat die X (center part) are rolled in the rolling direction. The biting part A, the finishing part B, and the relief part C which differ in the inclination angle with respect to the rolling direction in order from a start end side are formed continuously. The rolled teeth 2 are formed by grinding a die base material with which the outer shape is previously processed to a predetermined dimension.

The finishing portion B is along the surface parallel to the bottom surface 9 (dice reference surface) in the rolling direction, and the biting portion A is along the surface inclined toward the bottom surface toward the starting direction in the rolling direction. The relief part C follows the surface which inclines toward the bottom surface side toward the end direction of the rolling direction.

Therefore, the pair of flat dice X disposed to face each other are moved relative to each other in the opposite direction, so that the intervals are different in the biting portion A, the finishing portion B, and the relief portion C (specifically, the finishing portion ( The gap becomes narrowest at B), and the rolled member 1 inserted into the pair of flat dice X is applied with pressure while being rotated, and the tooth F of the worm or screw (threaded) ) Is formed.

In this embodiment, the shape of the tooth part 3 has a substantially trapezoidal shape when viewed from a cross section or a substantially triangular shape when viewed from a cross section where its thickness (tooth thickness T) becomes smaller toward this end side, and the tooth groove 5 Contrary to the tooth part 3, the shape of is substantially trapezoidal in cross section, which becomes smaller toward the bottom side, or forms a substantially triangular shape in cross section. This bottom edge part is made into substantially circular arc shape (ar shape) by the cross section which becomes convex toward the tooth part 3 side.

In addition, at both end portions (both ends in the direction orthogonal to the rolling direction) of the flat dice X, as shown in Fig. 3, each tooth 3 has a predetermined chamfering angle α (to the upper surface of the rolling tooth die 2). The chamfer 4 which is chamfered in 20-60 degrees) is formed. This chamfer 4 is formed in order to suppress the defect of the tooth | gear part 3 of the dice side edge part. If the chamfer angle α is smaller than 20 °, the distance of the chamfer becomes long, and the incomplete screw (tooth) part area of the target member 1 becomes long. Therefore, it is not practical, and if it exceeds 60 °, the tooth 3 of the die It is not preferable because it becomes too thin and brittle. Generally, 30 degrees, 45 degrees, and 60 degrees are employ | adopted. In this embodiment, the chamfer angle α is set to 30 degrees. On the other hand, in the chamfering part 4, in the present embodiment, the biting part A, the finishing part B, and the relief part C are ground at a predetermined angle to form the tooth groove 5 (tooth part 3). It forms in the former die base material using the general well-known plane grinding mill.

By the way, in the conventional flat dice X ', the plurality of teeth 3' are equally arranged in a meandering state in the rolling direction at predetermined intervals, and as shown in Figs. A chamfer 4 'is formed in which each tooth 3' is chamfered with a predetermined chamfer angle α with respect to the upper surface of the rolled tooth 2 '. In such a configuration, since the upper part of the tooth 3 'is partially removed in the chamfer 4', the deficiency of the tooth 3 'of the die side end portion 8' can be suppressed. Although the contact area between the teeth of the tooth and the teeth 3 'is reduced, but the contact area is tightly closed (the thickness T' is the same as the center part at the side end portions 8 '), the above-described configuration of the background art As described above, the edge of the chamfered portion 4 '(edge of this end) interferes with the tooth surface of the tooth of the member to be rolled, so that scratches and burrs tend to occur relatively. In the figure, 5 'is a tooth groove, 6' is this bottom, and 7 'is this end.

In this regard, in this embodiment, as shown in Fig. 4. 5, both side end portions 8 of the bottom 6 of the rolling teeth 2 are placed on the upper surface of the rolling teeth 2 (or the bottom surface of the die). (9) (dice reference surface)) by inclining downhill at a predetermined angle outward with respect to a straight line parallel to the straight line, the tooth thickness T of each tooth 3 in the chamfer 4 becomes a predetermined height position (this end). The tooth 3 of the rolling tooth 2 and the tooth 1 of the rolled member 1 so as to become thinner than the center portion at a predetermined position in the tooth height region from the bottom to the bottom, for example, the straight line D. The clearance gap G is formed between (F) (FIG. 4), and the chamfered part 4 of the tooth F of the to-be-rolled member 1 is influenced by the progress of the to-be-rolled member 1, or the influence of mechanical rigidity. ), An interference mitigating portion (R) for mitigating interference between the tooth (3) and the member to be rolled (1) is constructed so as to avoid contact with each other.

Specifically, the tooth groove 5 of the rolled tooth 2 is formed on the outside perpendicular to the rolled direction with respect to a straight line parallel to the upper surface of the rolled tooth 2 (or the bottom surface 9 (dice reference plane) of the die). The side end portions 8 of the bottom 6 are formed by being formed along the direction inclined at a predetermined angle toward the bottom surface side, and the inclination toward the bottom surface side is called a downhill slope.

That is, only by inclining this bottom 6 in the chamfer part 4 of the rolled tooth 2 to a predetermined angle, it is accompanied by the contact with the to-be-rolled member 1 which arose in the conventional chamfer part 4 '. It becomes possible to solve the problem.

In addition, in the present embodiment, the interference mitigation portion R is formed over the entire length of the flat dice X, but since the problem of scratches and burrs is unlikely to occur in the biting portion A, at least the finishing portion B ) And the relief portion C, a sufficient effect can be obtained.

Incidentally, the inclination angle β of both side end portions 8 of the bottom 6 is a straight line parallel to the bottom surface 9 (dice reference surface) of the die (in this embodiment, the rolling tooth shape 2 is used as a finishing portion ( It is set at an angle greater than 0 ° and within 60 ° with respect to the straight line parallel to this end 7 in the center of B). By making the inclination angle, the tooth thickness T at a predetermined height position becomes thin and the groove width becomes large (the gap G between the to-be-rolled member 1 and the teeth 3 of the chamfer 4 becomes large).

Specifically, the inclination angle β of both side end portions 8 of the bottom 6 is the same angle as the chamfer angle α or greater than the chamfer angle α, and the finish portion ( It is set at an angle within 60 ° with respect to a straight line parallel to this end 7 of the center of B). If the angle exceeds 60 °, the angle is too large, and the production efficiency of the die is deteriorated (the grinding time increases), which is not preferable. In this embodiment, the chamfering angle α and the same angle β (30 °) are set.

In addition, in order to further prevent injuries and the like from occurring in the teeth F of the rolled member 1, it is preferable to set the corners of the teeth 3 of the rolled teeth 2 so as to be smoothly connected to the curved surface. .

Specifically, in the present embodiment, the shape of the teeth 3 has a substantially trapezoidal shape when viewed from a cross section or a substantially triangular shape when viewed from a cross section such that its thickness (tooth thickness T) becomes smaller toward this end side. In contrast to the tooth 3, the tooth groove 5 has a substantially trapezoidal shape in cross section or a substantially triangular shape in cross section, the width of which decreases toward the bottom side. Although it has the rolling tooth shape 2 which becomes substantially circular arc shape (ar shape) from the cross section which becomes convex toward (3) side, and has interference interference | restoration part R, this interference relaxation part R is a chamfer part. Both side end parts 8 of this bottom 6 of (4) can be formed only by inclining a predetermined angle. That is, the rolling teeth 2 are formed by using a grindstone having teeth of approximately the same shape as the shape of the tooth groove 5 in the center portion perpendicular to the rolling direction of the die, and both side ends of the rolling teeth 2. In the region 8, a thin tooth 3 is formed by grinding the grindstone deeper (in the direction of the bottom surface of the dice) to form a deeper tooth groove 5 than in the case of forming the tooth 3 in the center portion, The interference mitigation section R is configured. Therefore, it is not necessary to change the grindstone according to the site (it is only necessary to change the conventional rolling tooth shaping program), and it is possible to form each tooth 3 (tooth groove 5) by the same grindstone. do. In this case, the shape of the tooth groove 5 between the teeth 3 of the rolled tooth 2 is approximately the same shape (the same shape in the region of the groove bottom side where the shape of the corner portion of this tip does not affect). )

On the other hand, in the present embodiment, as described above, the interference mitigation portion R is formed by inclining both side end portions 8 of the bottom 6 of the chamfer 4 at a predetermined angle. As in Exemplary Example 1 shown in Fig. 8, the interference is alleviated by forming the teeth 3 at both ends thinner than the central part in the direction perpendicular to the rolling direction of the die, without inclining both side end portions 8 of the bottom 6. You may comprise the part R. In this case, without changing the grindstone W (just changing the conventional rolling tooth shaping program), at narrower intervals than the case where the central teeth 3 are formed at both ends of the flat dice X. It is sufficient to form a thin tooth 3 by grinding the width of the tooth groove 5 to be wider, and a gap G is formed between the target member 1 and the widened tooth groove 5 (Fig. 8). I is an imaginary line of the member 1 to be transmitted). The means constituting the interference mitigating portion R is effective for teeth of a substantially rectangular shape when viewed from a tooth shape or a cross section in which the shape of the tooth groove 5 is not so small in width toward the bottom side. In this case, in the cross section orthogonal to the rolling direction, the shape of the tooth grooves 5 at both side end portions 8 of the rolling teeth 2 is in the direction orthogonal to the shape of the tooth grooves 5 in the center portion. The shape becomes substantially the same as the trajectory obtained by the parallel movement (the same shape in the groove bottom region where the shape of the corner portion of the tip does not affect).

In addition, although the interference alleviation part R is formed in the both ends of the rolled tooth 2 in this embodiment, for example, a screw part is short and does not get caught by the both ends of a die, but is one side end part (chamfered). According to the target member 1 to be processed, such as a screw which does not interfere with the base 4, it is good also as a structure formed only in one side end part, without forming in both side ends.

In addition, although this embodiment is the example which applied this invention to the flat dice X, it is the same also in the other example 2 applied to the substantially cylindrical round dice Y as shown in FIG. As for the round die Y, the whole circumference is equivalent to the finish part of the flat dice X, Specifically, the rolling tooth shape 2 of the round die Y (center part) has the distance r from a rotation axis to this end. It is formed so that it may follow a fixed circumferential surface, and the interference alleviation part R is formed over the whole circumference of the round dice Y. The rolling tooth die 2 is formed by grinding a die base material that is externally processed to a predetermined dimension in advance.

The description about the case of the flat dice X mentioned above is applicable also to the round dice Y. That is, the rotation direction of the round die Y is a rolling direction, and the bottom surface 9 (dice reference surface) which becomes a reference | standard of the angle of inclination of this floor in the chamfer (or side end part) of the rolling tooth shape in the flat dice X. Is replaced with the rotation axis (reference line) L of the round die (Y). In the round die Y, like the flat dice X, the chamfers are formed at the side ends (both ends or one end in the rotation axis direction), but the chamfers are inclined at the side ends of the bottom as in the present embodiment. Specifically, in FIG. 11, both side end portions 8 of the bottom 6 of the rolling teeth 2 are rotated on the upper surface of the rolling teeth 2 (or the rotation axis of the round die Y (dice reference line L)). By inclining downhill at a predetermined angle outward with respect to the straight line parallel to the teeth, the tooth thickness T of each tooth in the chamfer 4 becomes a predetermined height position (a predetermined position in this height region from this end to this floor). For example, it becomes thinner than the center part in the straight line D. In Fig. 11, the right side is a fixed die, the left side is a moving dice, and the reference Z is illustrated as a work rest. 1) is conveyed and installed, the moving die on the left is moved closer to the fixed die on the right side, and the outer peripheral surface of the to-be-rolled member 1 is inserted so as to plastically deform by a predetermined amount. It is rolled by rolling.

In addition, the same applies to the other example 3 applied to the so-called vacancy die Q of a shape in which a part of the outer circumference of the substantially cylindrical round die as shown in FIG. 12 is cut out. The description about the case of the flat dice X described above is also applicable to the vacancy dice Q. That is, the rotation direction of the vacancy die Q is a rolling direction, and the bottom surface 9 (dice reference surface) which becomes a reference | standard of the angle of inclination of this floor in the chamfer (or side end part) of the rolling tooth shape in the flat dice X is shown. Is replaced with the rotation axis (reference line) L of the vacancy die Q.

On the other hand, the rolling tooth shape 2 of the vacancy die Q (center part) has the biting part A from which the distance r from this rotation axis to this end (henceforth a radius r) differs in sequence from a rolling direction start side. ), The finishing portion (B) and the relief portion (C) are formed continuously. The rolling tooth die 2 is formed by grinding a die base material that is externally processed to a predetermined dimension in advance.

The finishing portion B is along the circumferential surface of which radius r is constant in the rolling direction, and the biting portion A is along the circumferential surface of which the radius r becomes smaller toward the starting direction in the rolling direction, and the relief portion C is rolling. Along the circumferential surface, the radius r becomes smaller toward the longitudinal end side.

Therefore, the pair of vacant dies Q which are arranged to face each other rotate in synchronism, whereby the intervals are different in the biting part A, the finishing part B, and the relief part C (specifically, the finishing part). In (B), the gap becomes narrowest), and the rolled member 1 inserted into this pair of vacancy dies Q is exerted with pressure while being rotated, and the teeth F of the worm or screw ( Thread) is formed.

The chamfered part is formed also in the side edge part (both end part or one end part of a rotating shaft direction) like vacancy dice X in the vacancy die Q, but this side chamfer is inclined in this chamfer part like this embodiment. Specifically, in FIG. 12, both side end portions 8 of the bottom 6 of the rolling teeth 2 are rotated on the upper surface of the rolling teeth 2 (or the rotation axis of the vacancy die Q) (dice reference line L). By inclining downhill at a predetermined angle outward with respect to the straight line parallel to the teeth, the tooth thickness T of each tooth in the chamfer 4 becomes a predetermined height position (a predetermined position in this height region from this end to this floor). For example, it becomes thinner than the center portion in the straight line D. In Fig. 12, fixed distances (interaxial distance set so that the outer peripheral surface of the member 1 to be plastically deformed by a predetermined amount after rolling) are fixed. The to-be-rolled member 1 supported by the pair of vacancy dice Q and the center which is not shown is illustrated.

The pair of vacancy dies are supported by the rolled member 1 supported by a center (not shown) in a state in which the cutout portions P of the pair of vacancy dies Q face each other. Into the space formed by the cutout part P of (Q), it is conveyed and installed in a predetermined position, and the said pair of vacancy dies are rotated synchronously and rolled so that the outer peripheral surface of the to-be-rolled member 1 may be plastically deformed by predetermined amount. It is processing.

Since the present embodiment is constituted as described above, when the rolled member 1 is sandwiched by a pair of rolled dies and rolled, the rolled teeth 2 have a thin side end portion T which is thin in thickness. A gap G is formed between the tooth portion 3 of the tooth member 3 and the portion to be engaged with the tooth portion 3 of the target member 1. ), Interference with is reduced.

Therefore, in the case of finishing rolling, it is possible to prevent the occurrence of a wound on the tooth surface of the to-be-rolled member 1, and in the case of the solid rolling, it is possible to prevent the occurrence of burr at the end of the to-be-rolled member 1, The shift of the to-be-rolled member 1 can also be suppressed further.

Specifically, the experimental example of the precursor of a worm is demonstrated. In the case of finishing rolling, the interference between the chamfer 4 and the target member 1 is alleviated, so that the teeth at the side end portions of the wound as shown in Fig. 9 (a) or the rolling tooth shape as shown in Fig. 9 (b) are reduced. Defects are suppressed, and in the case of solid rolling, it is possible to suppress the burr as shown in FIG. 10 (b) without producing a burr as shown in FIG. 10 (a). Worm shaft) The deviation at the tip can be reduced by 66% from 0.394 mm to 0.133 mm, and the deviation of the worm part can be reduced by 88% from 0.225 mm to 0.027 mm. As shown in FIG. 13, the value of this misalignment is the front end portion (cylindrical shape) of the said worm shaft and the intermediate part of the said worm shaft on the basis of the two-point support of the cylindrical worm shaft as the to-be-rolled member 1, and FIG. It is measured at the worm section rolled on the.

Therefore, the present embodiment is extremely superior in practicality in that interference between the rolled member and the rolled tooth of the die is suppressed as much as possible to prevent the occurrence of scratches or burrs on the tooth surface of the rolled member.

1: member to be rolled
2: roll tooth
3: chibu
5: Chihom
6: this floor
8: side end part
A: Biting part
B: finish
C: relief part
Q: Vacancy Dies
R: interference mitigation section
T: tooth thickness
X: Plain dice
Y: round dice

Claims (19)

A rolling die for rolling a tooth of a worm or a screw by plastic deformation of the outer circumferential surface by bringing a rolling tooth into contact with an outer circumferential surface of a member to be rolled, wherein at least one end of the rolling tooth is formed at each tooth. An interference mitigating portion is formed so as to be thinner than the central portion at a predetermined height position to mitigate interference with the to-be-rolled member, and the interference mitigating portion is a tooth groove between each tooth of the rolling tooth shape. The inclined angle of the bottom end of the rolling tooth shape is inclined downward at a predetermined angle toward the outside, and the inclination angle of the bottom end portion of the rolling tooth is the same as that of the rolling die. It is set at an angle greater than 0 degrees and within 60 degrees with respect to a reference plane or a straight line parallel to the reference line, and each tooth of at least one side end of the rolling tooth shape is the front teeth. A rolling die characterized by being chamfered with a chamfer angle greater than 20 ° and within 60 ° with respect to the reference plane or a straight line parallel to the reference line. The angle of inclination of the side end portion of the bottom is an angle equal to or greater than the chamfering angle, and an angle within 60 ° with respect to a straight line parallel to the reference plane or reference line of the rolling die. Rolling dice characterized in that the set. A rolling die that plasticizes the outer circumferential surface to contact the outer circumferential surface of the member to be rolled to roll the teeth of a worm or screw, wherein at least one end of the rolling tooth has a central thickness at a predetermined height position. An interference mitigating portion is formed which is thinner than that to mitigate interference with the to-be-rolled member, and the interference mitigating portion has a shape of the tooth groove between the teeth at the side end of the rolling tooth shape at a cross section orthogonal to the rolling direction. In view of the above, the shape of the tooth groove in the center portion is configured to have the same shape as the trajectory obtained by the parallel movement in the direction orthogonal to this rolling direction, and each tooth of at least one end of the rolling tooth shape is a reference surface of the rolling die or It is chamfered with a chamfer angle greater than 20 ° and within 60 ° with respect to a straight line parallel to the reference line. Rolling dice made with. The rolling die according to any one of claims 1 to 3, wherein the biting portion, the finishing portion, and the relief portion are sequentially formed in order from the starting direction side of the rolling direction. It is a flat dice, The said interference relief part is formed in at least the said finish part and the relief part, The rolling dice characterized by the above-mentioned. The rolling die according to any one of claims 1 to 3, wherein the rolling die is a round die, and the interference damping portion is formed over the entire circumference of the round die. The rolling die according to any one of claims 1 to 3, wherein the rolling die is a vacancy die formed by successively forming a biting portion, a finishing portion, and a relief portion from the starting direction in the rolling direction. And at least the finishing section and the relief section, wherein the rolling die is formed. The rolling die according to claim 4, wherein the interference mitigating portion is formed at both end portions of the rolling teeth. The rolling die according to claim 5, wherein the interference mitigating portion is formed at both end portions of the rolling teeth. The rolling die according to claim 6, wherein the interference mitigating portion is formed at both end portions of the rolling tooth. delete delete delete delete delete delete delete delete delete delete

Images