JP2003117629A - Internal gear die device, and crowning internal gear die device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal gear die device which can form an internal gear of high quality, and a crowning internal gear die device which can form an internal gear into a crowning internal gear. SOLUTION: A forming space (a) in which an annular work W is fitted is formed by an annular first container 6 and a columnar first mandrel 10. A first forming tooth 11 which is formed into a finishing tooth of a tooth profile substantially equal to the tooth of the internal gear intended for the downstream side is provided on a preliminary forming tooth of the tooth profile of the negative transition to the internal gear tooth intended for the upstream side, and a first punch 13 to move the work W fitted in the forming space (a) downwardly is provided on the outer circumference of the first mandrel 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold device for extruding an internal gear and a mold device for molding teeth of the internal gear into crowning teeth.

[0002]

2. Description of the Related Art Molding teeth of a conventional mold device for extruding and molding an internal gear are as shown in FIG. In FIG. 8, reference numeral 2 denotes a helical molding tooth formed on the outer circumference of a cylindrical mandrel 1, which is inclined at a predetermined angle with respect to the axis of the mandrel 1 and is formed at a predetermined pitch in the circumferential direction. Axial intermediate portion 2a of the helical molding tooth 2
Has a tooth profile (cross-sectional shape) equal to the tooth of the target helical internal gear, and the upstream side 2b to which the material is supplied has an inclined surface that gently rises. The mandrel 1 is fitted into the axial center of a cylindrical container (not shown), and an annular material is passed between the two through a punch, so that the helical molding tooth 2 is used to form a helical shape on the inner circumference of the material. I was trying to form teeth.

[0003]

SUMMARY OF THE INVENTION In the above-mentioned conventional mold device for an internal gear, the axially intermediate portion 2 of the helical molding tooth 2 is used.
Since the whole area of a has the same tooth shape as the tooth of the helical internal gear, the inner peripheral portion of the material is plastically deformed at once, and it is difficult to smoothly perform the plastic flow of the material.
An unfilled portion is generated at a part of the tooth tip, and the reduction rate of the cross-section is increased, so that a large load is generated on the helical molding tooth 2, which easily wears and damages. Moreover, the conventional mold device cannot mold the teeth of the internal gear into the crowning teeth. The present invention provides a mold device for an internal gear, in which an unfilled portion is less likely to occur, and a mold device for a crowning internal gear, which molds the teeth of the internal gear into crowning teeth while reducing the load applied to the molding teeth. The purpose is to get.

[0004]

The present invention is configured as follows to achieve the above object. That is, the invention according to claim 1 is the first as a mold device for an internal gear.
A molding space in which an annular material is fitted is formed by the container and a first mandrel that fits in the axial center portion of the first container, and a first molding tooth is circumferentially defined on the outer circumference of the first mandrel. Provided at a pitch, the first molding tooth is a pre-shaped tooth with a tooth profile that is a negative shift from the tooth of the internal gear intended for the upstream side where the material is supplied, and the downstream side where the material is discharged is targeted And a finish-molded tooth having a tooth shape substantially equal to that of the tooth of the internal gear, and the pre-molded tooth has its upstream side raised at a predetermined inclination angle, and after extending the raised portion by a predetermined amount to the downstream side, The first punch is configured to have its downstream end raised at a predetermined inclination angle and connected to the finish forming tooth, and to provide a first punch for moving the material fitted in the forming space downward. The invention according to claim 2 is
The first molding tooth is a helical molding tooth, the first container,
The first mandrel and the first punch are rotatable about the axis of the first container. Claim 3
The invention according to, as a mold device for a crowning internal gear, forms an annular second molding space in which the internal gear is fitted by a collet and a second mandrel fitted in the axial center of the collet, On the outer circumference of the second mandrel, crowning molding teeth whose tooth thickness at the center in the axial direction is thinner than the tooth thickness at both ends in the axial direction are provided at a predetermined pitch in the circumferential direction, and the lower side has a large diameter on the outer circumferential surface of the collet. A second punch that slidably fits an annular collet presser through the conical surface, and the outer circumference of the collet presser is slidably fitted to a second container, and the collet presser is moved downward. It is configured to be provided. In the invention according to claim 4, the crowning molding tooth is a crowning helical molding tooth.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a mold device for an internal gear according to the present invention, FIG. 1 is an explanatory sectional view showing an operating state of the mold device, and FIG. 2 is a partially enlarged explanatory view of a first molding tooth portion. 3 is the first
FIG. 4 is a partially enlarged perspective view of a molded tooth portion, and FIG. 4 is a partially enlarged perspective view of an internal gear molded by the present invention.

In FIG. 1, 5 is a mold device for an internal gear,
6 is the first container, and 10 is the first mandrel arranged at the axial center of the first container 10. The first container 6 is fitted and held by a clamp 7 and rotatably mounted on the lower plate 8, and is vertically moved by a predetermined amount with respect to the lower plate 8 by a cylinder (not shown). ing. The first container 6 has a circular insertion hole 6a through which the ring-shaped material W passes, and the first mandrel 10 is concentrically fitted into the insertion hole 6a so that the material W is interposed therebetween. To form an annular molding space (a).

The first mandrel 10 has a lower plate 8
Is rotatably mounted on the lower surface of the first molding tooth 11 and
Are formed at a predetermined pitch in the circumferential direction. The first forming tooth 11 is a helical forming tooth that is inclined at a predetermined angle with respect to the axis of the first mandrel 10, and as shown in FIGS. 11a, and the downstream side from which the material W is discharged is the finish forming tooth 11b. The preformed tooth 11a is formed in a tooth profile in which the tooth of the target internal gear is shifted by a minus shift. That is, the diameter D2 of the root circle, the diameter D4 of the addendum circle, and the tooth thickness are made slightly smaller than those of the internal gear, and the upstream side 11a-
The tooth tip of No. 1 is raised at a gentle angle such that the inclination angle α is about 15 degrees, and the raised portion 11a-2 is extended by a predetermined amount toward the downstream side.

The finish-molded teeth 11b are formed in a tooth shape that is substantially the same as the teeth of the target internal gear. That is, the diameter D3 of the root circle, the diameter D5 of the addendum circle, and the tooth thickness of the internal gear that is the target are made substantially equal to each other, and the addendum portion of the upstream side 11b-1 is the addendum of the preforming tooth 11a. From the downstream end of the prefabricated tooth 11a at a radius R of about 45 mm from the downstream end of the preforming tooth 11a. The part is raised by an arc, and these rising parts 11b-2 are extended by a predetermined amount toward the downstream side. In addition, the first mandrel 10 described above
The diameter D1 on the upper side of the is slightly smaller than the diameter D2 of the root circle of the preformed tooth 11a. The first molding tooth 11
May be a spline tooth forming tooth parallel to the axis of the first mandrel 10.

The first container 6 and the first mandrel 10 described above.
The cylindrical first punch 13 is arranged above the. The first punch 13 is moved up and down by a ram so that its lower end can be inserted into and removed from the above-mentioned annular molding space (A), and when it is moved downward, the first punch 13 is inserted into the molding space (A). The fitted material W is pressed and moved downward. In the molding space (a), for example, three materials W1, W2
W3 are sequentially overlapped and fitted, and each time the first punch 13 makes one downward movement, one material W is provided for each first molding tooth 11
Helical teeth are formed on the inner peripheral surface of the material W after passing through the section.

In this case, when the first punch 13 is moved downward, the first container 6 and the first mandrel 10 are moved downward and hit the lower plate 8 as shown in the left half of FIG. And the lowermost material W1 passes through the first molding tooth 11 part to form helical teeth on the inner peripheral surface of the material W1.
As shown in FIG. 4, a helical internal gear 14 having helical teeth 14a on its inner circumference is obtained. Then, the first punch 1
When 3 is moved upwards, as shown in the right half of FIG. 1,
The first container 6 is moved upward by a predetermined amount by a cylinder (not shown), and along with this, the first mandrel 10 is moved upward by a predetermined amount via the material W interposed in the molding space (a). As a result, the take-out space (a) is formed in the upper portion of the lower plate 8 and the internal gear 14 (the material W1 having the helical teeth formed thereon) that has fallen onto the lower plate 8 can be taken out. The first punch 13 is then removed from FIG.
As shown by the phantom line, the upper part is moved further upward and separated from the first container 6 and the first mandrel 10, so that a new material W can be fitted into the molding space (a) from above.

5 and 6 show a mold device for a crowning helical internal gear according to the present invention, FIG. 5 is an explanatory sectional view showing an operating state of the mold device, and FIG. 6 is an enlarged sectional view of an essential part. 7 is a partially enlarged perspective view of the crowning helical internal gear formed by the present invention. In FIG. 5, reference numeral 20 denotes a mold device for a crowning helical internal gear, which forms the helical tooth 14a of the helical internal gear 14 described above into a crowning helical tooth.

The mold device 20 for the crowning helical internal gear is as follows. That is, the cylindrical second mandrel 22 is rotatably mounted on the axial center of the lower plate 21, and the annular collet 27 is rotatably mounted on the outer periphery of the lower plate 21 via the deposit 25 and the intermediate plate 26. It is placed and an annular second molding space (reference numeral omitted) in which the helical internal gear 14 described above is fitted is formed between the collet 27 and the second mandrel 22. The second mandrel 22 is rotatably mounted on the lower plate 21 by coaxially connecting an upper mandrel 22a and a lower mandrel 22b, which are divided into upper and lower parts, with a core metal 23, and crowning helical molding on the lower outer periphery of the upper mandrel 22a. The teeth (crowning molding teeth) 24 are formed at a predetermined pitch in the circumferential direction.

The crowning helical molding teeth 24 are
The helical tooth 14a of the helical internal gear 14 described above is molded into a crowning helical tooth, which is inclined at a predetermined angle with respect to the axis of the second mandrel 22, and
The crowning helical molding tooth is such that the tooth thickness at the center in the axial direction is thinner than the tooth thickness at both ends in the axial direction. In the case where the teeth of the internal gear are flat teeth in which the teeth of the internal gear are parallel to the axial direction, the crowning helical molding teeth 24 are parallel to the axial direction correspondingly, and the tooth thickness at the center of the axial direction is at both axial ends. The crowning molding tooth is a flat tooth that is thinner than the tooth thickness of the part.

The outer peripheral surface of the collet 27 is a conical surface 27a having a large diameter downward, and an annular collet retainer 28 is slidably taper fitted to the outer peripheral surface of the collet 27. The collet retainer 28 is vertically slidably fitted to a second container 29 fitted and fixed to the upper plate 30. Reference numeral 31 is a regulation plate that regulates the upward movement of the collet retainer 28. A cylindrical counter punch 32 is vertically movably fitted in a gap between the intermediate plate 26 and the lower mandrel 22b, and its lower end is placed on the lower plate 21. The upper part of the counter punch 32 is the second
Positioned so that the helical internal gear 14 is fitted to the lower side in the molding space and supports and supports the lower surface of the helical internal gear 14 fitted in the second molding space so that the helical internal gear 14 faces the crowning helical molding teeth 24. To do. Reference numeral 33 is a knockout pin that moves the counter punch 34 upward, and is used to push a molded product (crowning helical internal gear 40) molded by the crowning helical molding teeth 24 upward from the second molding space. .

The collet 27 and the second mandrel 22.
A cylindrical second punch 35 and a third punch 36 are arranged above the. The first and second punches 35 and 36 are independently moved up and down, the second punch 35 moves the collet presser 28 downward by a predetermined amount at the lower end when the second punch 35 moves downward, and the third punch 36 lowers at the lower end when it moves downward. Then, the upper surface of the helical internal gear 14 fitted in the second molding space is pressed. When molding, first, the third punch 36 moves downward to press the upper surface of the helical internal gear 14 in the second molding space at the lower end thereof, and then the second punch 35 moves downward to move the above at the lower end thereof. The collet presser 28 is moved downward by a predetermined amount. Then, as shown in the left half of FIG. 5, the collet retainer 28 elastically deforms the collet 27 in the axial direction through its tapered surface, and the collet 27 is fitted into the second molding space accordingly. The combined helical internal gear 14 is elastically deformed in the axial direction.

As a result, the helical tooth 14a of the helical internal gear 14 is pressed against the crowning helical molding tooth 24 and is plastically deformed, and as shown in FIG. 7, the tooth thickness at the axial center is equal to that at both axial ends. The crowning helical internal gear 40 having the crowning helical internal teeth 40a thicker than the tooth thickness is formed. In this example, the swelling amount S on one surface of the central portion in the axial direction is set to about 10 μm. When the second punch 35 is moved upward, as shown by the phantom line in FIG.
7 and the crowning helical internal gear 40 elastically return to a large diameter, and the crowning helical internal gear 40 can be easily detached from the mold device 20 to the outside.

[0017]

As is apparent from the above description, in the die device for an internal gear according to the present invention, the first molding tooth formed on the outer periphery of the first mandrel is the tooth of the internal gear intended for the upstream side. Since it is a preformed tooth with a negative shift and a finish molding tooth that is approximately the same as the tooth of the internal gear targeted for the downstream side, the tooth of the internal gear is formed by squeezing the material in two stages. As a result, the internal gear can be formed with a smaller cross-sectional reduction rate than in the conventional case, and the flow of the material becomes smooth, so that the occurrence of unfilled tooth tips is reduced. Further, since the cross-sectional reduction rate is small, the load applied to the first molding tooth is small and the life of the first molding tooth is extended. Further, the mold device for the crowning internal gear according to the present invention,
The annular collet and the cylindrical second mandrel form an annular second molding space into which the internal gear is fitted,
A crowning molding tooth is formed on the outer periphery of the mandrel so that the tooth thickness at the center in the axial direction is thinner than the tooth thickness at both ends in the axial direction, and an annular collet retainer is provided on the outer periphery of the collet with a conical surface with a large diameter downward. Taper fitting, the outer circumference of the collet holder is slidably fitted to the second container, and the collet holder is moved downward by the second punch. When it is moved downward, the internal gear is elastically deformed to a small diameter via the collet, and the internal teeth are pressed against the crowning molding teeth. As a result, the internal gear is molded into crowning teeth without moving in the vertical direction. In addition, the crowning internal gear molded into the crowning teeth is released from the die device to the outside easily by elastically returning the collet and the crowning internal gear to a large diameter by releasing the pressure of the second punch. Can be made.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view showing an operating state of a mold device for an internal gear according to the present invention.

FIG. 2 is a partially enlarged explanatory view showing a first molding tooth portion.

FIG. 3 is a partially enlarged perspective view showing a first molding tooth portion.

FIG. 4 is a partially enlarged perspective view of an internal gear molded according to the present invention.

FIG. 5 is an explanatory sectional view showing an operating state of the mold device for the crowning helical internal gear according to the present invention.

6 is an enlarged cross-sectional view of a main part of FIG.

FIG. 7 is a partially enlarged perspective view of a crowning helical internal gear molded according to the present invention.

FIG. 8 shows molding teeth of a conventional mold device for an internal gear.

[Explanation of symbols]

5 Mold device for internal gear 6 First container 6a Insertion hole 7 Clamp 8 Lower plate 10 First mandrel 11 First molding tooth (helical molding tooth) 11a Pre-molding tooth 11a-1 Upstream side 11a-2 Standing up Part 11b Finish molding tooth 11b-1 Upstream side 11b-2 Standing part 13 First punch 14 Helical internal gear (internal gear) 14a Helical tooth (internal tooth) 20 Crowning Helical internal gear mold device (Molding device for crowning internal gear) 21 Lower plate 22 Second mandrel 22a Upper mandrel 22b Lower mandrel 23 Core metal 24 Crowning helical molding tooth (crowning molding tooth) 25 Deposit 26 Intermediate plate 27 Collet 27a Conical surface 28 Collet retainer 29 Second container 30 Upper plate 31 Control plate 32 Counter punch 33 Kuautopin 35 second punch 36 third punch 40 crowning helical internal gear (crowning in gear) 40a crowning helical teeth (crowning tooth)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shoichi Koyama             Fuji Co., Ltd. 2418 Washizu, Kosai City, Shizuoka Prefecture             In Univance (72) Inventor Yoshinori Sato             Fuji Co., Ltd. 2418 Washizu, Kosai City, Shizuoka Prefecture             In Univance F term (reference) 4E087 AA08 AA09 BA18 CA17 EC11                       EC38 HA04 HA08

Claims (4)

[Claims] 1. A molding space (a) in which an annular material (W) is fitted by a first container (6) and a first mandrel (10) which fits in the axial center of the first container (6). ) Is formed, and first molding teeth (11) are provided on the outer periphery of the first mandrel (10) at a predetermined pitch in the circumferential direction, and the material (W) is supplied to the first molding teeth (11). A preformed tooth (11a) with a tooth profile that is a negative shift from the tooth of the internal gear intended for the upstream side, and is approximately equal to the tooth of the internal gear intended for the downstream side from which the material (W) is discharged. A preformed tooth (11b) having the following tooth profile, the preformed tooth (11a) has its upstream side raised at a predetermined inclination angle, and after extending the raised portion by a predetermined amount to the downstream side, its downstream end is The finish molding tooth (1
1b), which is provided with a first punch (13) for moving a material (W) fitted in the molding space (a) downward, a die device for an internal gear. 2. The first molding tooth (11) is a helical molding tooth, and the first container (6), the first mandrel (10) and the first punch (13) are axial centers of the first container (6). The rotary unit according to claim 1 is rotatable about
Mold device for internal gear described. 3. A collet (27) and the collet (27).
An annular second molding space into which the internal gear (14) is fitted is formed by the second mandrel (22) fitted to the shaft center portion of the second mandrel, and an axial center portion is formed on the outer periphery of the second mandrel (22). The crowning molding teeth (24) whose tooth thickness is smaller than the tooth thicknesses at both ends in the axial direction are provided at a predetermined pitch in the circumferential direction, and the outer peripheral surface of the collet (27) has a conical surface (27a) whose downward diameter is large. ), An annular collet retainer (28) is slidably fitted, and the outer periphery of the collet retainer (28) is moved to the second position.
A second punch (3) fitted in a container (29) slidably up and down and moving the collet retainer (28) downward.
5) A mold device for a crowning internal tooth gear, characterized by being provided. 4. The mold device for a crowning internal gear according to claim 3, wherein the crowning molding teeth (24) are crowning helical molding teeth.