JP4603010B2 - Crowning internal gear molding method - Google Patents

Description

The present invention relates to a crowning internal gear molding method for molding teeth of an internal gear into crowning teeth.

  Conventionally, since the teeth of the internal gear cannot be formed into crowning teeth by the mold apparatus, they are formed by mechanical grinding.

It is an object of the present invention to obtain a crowning internal gear molding method for molding the teeth of an internal gear into crowning teeth while reducing the load applied to the molded teeth.

The present invention is configured as follows to achieve the above object. That is, the invention according to claim 1 forms a molding space in which an annular material is fitted by the first container and the first mandrel fitted to the axial center portion of the first container, and the first mandrel The first molded teeth are provided on the outer periphery at a predetermined pitch in the circumferential direction, and the first molded teeth are preliminarily tooth forms in which the upstream side to which the material is supplied is negatively displaced with respect to the teeth of the target internal gear. The downstream side from which the material is discharged is a finished molded tooth having a tooth profile that is substantially equal to the tooth of the target internal gear, and the upper side diameter of the first mandrel is the bottom circle of the preformed tooth. And the upstream side of the base of the preformed tooth is connected to the upper side of the first mandrel with a gentle slope, and the downstream side of the base of the preformed tooth is connected to the tooth of the finished molded tooth. Connect to the bottom upstream side with a gentle slope, and the tip of the preformed tooth The upstream side is raised toward the downstream side at a predetermined inclination angle, the raised portion is extended to the downstream side by a predetermined amount, and then the downstream end is raised at a predetermined inclination angle to add the tip of the finished molded tooth An internal gear is preformed by a mold device for an internal gear provided with a first punch for moving a material fitted in the molding space downward , and a collet and an axial center portion of the collet An annular second molding space into which the pre-formed internal gear is fitted is formed by a second mandrel fitted into the second mandrel, and the tooth thickness at the axial central portion is at the axial end portions on the outer periphery of the second mandrel. The crowned molding teeth that are thinner than the tooth thickness are provided at a predetermined pitch in the circumferential direction, and an annular collet presser is slidably fitted to the outer peripheral surface of the collet through a conical surface having a large diameter on the lower side, The outer circumference of the collet presser is the second container Vertically slidably fitted, it is obtained by the configuration in which finished molded by the mold apparatus of the crowning in gear with a second punch for moving said collet retainer downward.
According to a second aspect of the present invention, the crowning molded tooth is a crowning helical molded tooth.

  In the invention of the present application, an annular second molding space in which an internal gear is fitted is formed by an annular collet and a cylindrical second mandrel, and the tooth thickness at the axial center is axial on the outer periphery of the second mandrel. Forming a crowned molded tooth that is thinner than the tooth thickness at both ends in the direction, taperingly fitting the annular collet presser to the outer periphery of the collet through a conical surface having a large diameter at the bottom, and the outer periphery of the collet presser The collet presser is fitted to the second container so as to be slidable up and down, and the collet presser is moved downward by the second punch. Therefore, when the collet presser is moved downward by the second punch, the collet presser is moved through the collet. The tooth gear is elastically deformed to a small diameter, and the inner teeth are pressed against the crowning molded teeth. As a result, the internal gear is molded into crowning teeth without being moved in the vertical direction. In addition, the crowning internal gear formed on the crowning teeth releases the pressure of the second punch so that the collet and the crowning internal gear elastically return to a large diameter and can easily be removed from the mold apparatus to the outside. Can be made.

  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 a sectional view for explanation showing an operating state of the mold device, and FIG. 2 is a partially enlarged explanatory view of a first molded tooth portion, FIG. 3 is a partially enlarged perspective view of the first molded tooth portion, and FIG. 4 is a partially enlarged perspective view of the internal gear formed by the present invention.

In FIG. 1, 5 is a mold device for an internal gear, 6 is a first container thereof, and 10 is a first mandrel disposed at the axial center of the first container 6 . The first container 6 is fitted and held by a clamp 7 and is rotatably mounted on the lower plate 8, and is moved up and down 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 a ring-shaped material W passes at the axial center, and the first mandrel 10 is fitted concentrically into the insertion hole 6a so that the material W is interposed therebetween. An annular molding space (A) is formed in which is fitted.

  The first mandrel 10 is rotatably mounted on the lower plate 8, and first molding teeth 11 are formed on the outer periphery of the lower plate 8 at a predetermined pitch in the circumferential direction. The first molded tooth 11 is a helical molded tooth that is inclined at a predetermined angle with respect to the axial center line of the first mandrel 10, and the upstream side to which the material W is supplied is a pre-formed tooth as shown in FIGS. 11a, and the downstream side from which the material W is discharged is the finish molding tooth 11b. The pre-formed tooth 11a is formed in a tooth profile that is negatively displaced with respect to the tooth of the target internal gear. In other words, the diameter D2 of the root circle, the diameter D4 of the tip circle, and the tooth thickness are made slightly smaller than those of the internal gear, and the tooth tip portion on the upstream side 11a-1 has an inclination angle α of about 15. It rises at a gentle angle, and the raised portion 11a-2 is extended a predetermined amount toward the downstream side.

  The finish molding teeth 11b are formed in a tooth profile that is substantially equal to the teeth of the target internal gear. That is, the diameter D3 of the root circle, the diameter D5 of the tooth tip circle, and the tooth thickness are substantially equal to those of the internal gear, and the tooth tip portion on the upstream side 11b-1 is the tooth tip of the preformed tooth 11a. And the root portion of the upstream side 11b-1 is loose with a radius R of about 45 mm from the downstream end of the bottom portion of the preformed tooth 11a. The raised portion 11b-2 is extended by a predetermined amount toward the downstream side. Further, the diameter D1 on the upper side of the first mandrel 10 is slightly smaller than the diameter D2 of the root circle of the preformed tooth 11a. The first molded tooth 11 may be a flat tooth molded tooth parallel to the axis of the first mandrel 10.

  A cylindrical first punch 13 is disposed above the first container 6 and the first mandrel 10. The first punch 13 is moved up and down by a ram so that the lower end portion thereof can be fitted into and detached from the annular molding space (a) described above. When the first punch 13 is moved downward, the first punch 13 enters the molding space (a). The fitted material W is pressed and moved downward. In the molding space (a), for example, three materials W1, W2, and W3 are sequentially stacked and fitted, and each time the first punch 13 moves downward, the material W is first molded one by one. Helical teeth are formed on the inner peripheral surface of the material W through the teeth 11.

  In this case, when the first punch 13 is moved downward, the first container 6 and the first mandrel 10 are moved downward and come into contact with the lower plate 8 as shown in the left half of FIG. The lower material W1 passes through the first molded teeth 11 and helical teeth are formed on the inner peripheral surface of the material W1. As shown in FIG. 4, the helical internal gear 14 having helical teeth 14a on the inner periphery is formed. obtain. When the first punch 13 is moved upward, 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). The mandrel 10 is moved upward by a predetermined amount via the material W interposed in the molding space (a). Thereby, an extraction space (A) is formed in the upper part of the lower plate 8, and the internal gear 14 (the material W1 on which the helical teeth are formed) dropped on the lower plate 8 can be taken out. Thereafter, the first punch 13 moves further upward as shown by the phantom line in FIG. 1 to move away from the first container 6 and the first mandrel 10, and a new material W enters the molding space (a) from above. Can be fitted to.

  5 and 6 show the mold device for the crowning helical internal gear of the present invention, FIG. 5 is a sectional view for explanation showing the operating state of the mold device, FIG. 6 is an enlarged sectional view of the main part, and FIG. It is a partial expansion perspective view of the crowning helical internal gear formed by the 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. In other words, a cylindrical second mandrel 22 is rotatably mounted on the axial center portion of the lower plate 21, and an annular collet 27 is rotatable on the outer peripheral portion of the lower plate 21 via a washer 25 and an intermediate plate 26. An annular second molding space (reference numeral omitted) is formed between the collet 27 and the second mandrel 22 in which the helical internal gear 14 is fitted. The upper mandrel 22a and the lower mandrel 22b, which are divided into upper and lower parts, are coaxially connected by a cored bar 23 and are rotatably mounted on the lower plate 21. The second mandrel 22 is crowned helically molded on the lower outer periphery of the upper mandrel 22a. Teeth (crowning molding teeth) 24 are formed at a predetermined pitch in the circumferential direction.

  The crowning helical molding tooth 24 is formed by molding the helical tooth 14a of the helical internal gear 14 described above into a crowning helical tooth, and is inclined at a predetermined angle with respect to the axial center line of the second mandrel 22 and is axially centered. A crowning helical molded tooth in which the tooth thickness of the part becomes thinner than the tooth thickness at both ends in the axial direction. The crowning helical molded tooth 24 is parallel to the axial direction corresponding to the tooth of the internal gear parallel to the axial direction, and the tooth thickness at the axial center is axially opposite. A flat-toothed crowning tooth that is thinner than the tooth thickness of the part.

The collet 27 has a conical surface 27a with a large diameter on the outer peripheral surface, and an annular collet presser 28 is slidably taper-fitted to the outer peripheral surface of the collet 27. The collet presser 28 is fitted to a second container 29 fitted and fixed to the upper plate 30 so as to be slidable up and down. Reference numeral 31 denotes a restriction plate that restricts the upward movement of the collet presser 28. A cylindrical counter punch 32 is fitted in a gap between the intermediate plate 26 and the lower mandrel 22b so as to be movable up and down, and a lower end thereof is placed on the lower plate 21. The upper portion of the counter punch 32 is fitted to the lower side in the second molding space, and the lower surface of the helical internal gear 14 fitted in the second molding space is supported so that the helical internal gear 14 is crowned helical. Position so as to face the molding tooth 24. Reference numeral 33 denotes a knockout pin for moving the counter punch 32 upward. The knockout pin 33 is used to push the molded product (crowning helical internal gear 40) molded by the crowning helical molding tooth 24 upward from the second molding space. .

A cylindrical second punch 35 and third punch 36 are disposed above the collet 27 and the second mandrel 22. The second and third punches 35 and 36 are independently moved up and down, and the second punch 35 moves the collet presser 28 downward by a predetermined amount at the lower end when the second punch 35 is moved downward, and the third punch 36 is moved at the lower end when the lower punch is moved 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 down and presses the upper surface of the helical internal gear 14 in the second molding space at its lower end, and then the second punch 35 moves down and moves at the lower end to the above-mentioned The collet presser 28 is moved downward by a predetermined amount. Then, as shown in the left half part of FIG. 5, the collet presser 28 elastically deforms the collet 27 described above through its tapered surface in the axial direction, and is fitted in the second molding space accordingly. The combined helical internal gear 14 is elastically deformed in the axial direction.

  As a result, the helical teeth 14a of the helical internal gear 14 are pressed against the crowning helical molded teeth 24 and plastically deformed, and as shown in FIG. 7, the tooth thickness at the axial center is smaller than the tooth thickness at both axial ends. Thus, the crowning helical internal gear 40 having the crowning helical internal teeth 40a that is thicker is formed. In this example, the bulge amount S on one side of the central portion in the axial direction is set to about 10 μm. When the second punch 35 is moved upward, the collet 27 and the crowning helical internal gear 40 elastically return to a large diameter as shown by the phantom line in FIG. Can be easily detached from the mold apparatus 20 to the outside.

It is sectional drawing for description which shows the operating state of the metallic mold apparatus of the internal gear by this invention. It is a partial expansion explanatory view showing the 1st molding tooth part. It is a partial expansion perspective view which shows a 1st shaping | molding tooth part. It is a partial expansion perspective view of the internal gear gear shape | molded by this invention. It is sectional drawing for description which shows the operating state of the metal mold | die apparatus of the crowning helical internal gear by this invention. It is a principal part expanded sectional view of FIG. It is a partial expansion perspective view of a crowning helical internal gear molded by the present invention. It is a shaping | molding tooth | gear of the metal mold apparatus of the conventional internal gear.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Mold apparatus of internal gear 6 1st container 6a Insertion hole 7 Clamping 8 Lower plate 10 1st mandrel 11 1st molding tooth (helical molding tooth)
11a Preliminary molding tooth 11a-1 Upstream side 11a-2 Rising part 11b Finish molding tooth 11b-1 Upstream side 11b-2 Rising part 13 First punch 14 Helical internal gear (internal gear)
14a Helical teeth (inner teeth)
20 Molding device for crowning helical internal gear (molding device for crowning internal gear)
21 lower plate 22 second mandrel 22a upper mandrel 22b lower mandrel 23 cored bar 24 crowning helical molded tooth (crowning molded tooth)
25 Security deposit 26 Intermediate plate 27 Collet 27a Conical surface 28 Collet presser 29 Second container 30 Upper plate 31 Restriction plate 32 Counter punch 33 Knockout pin 35 Second punch 36 Third punch 40 Crowning helical internal gear (crowning internal gear)
40a Crowning helical teeth (crowning teeth)

Claims (2)

The first container (6) and the first mandrel (10) fitted to the axial center of the first container (6) form a molding space (A) in which the annular material (W) is fitted, The first molded teeth (11) are provided on the outer periphery of the first mandrel (10) at a predetermined pitch in the circumferential direction, and the first molded teeth (11) are on the upstream side to which the material (W) is supplied. The pre-formed tooth (11a) having a tooth profile that is negatively displaced with respect to the tooth of the internal gear and the tooth profile that is substantially equal to the tooth of the target internal gear on the downstream side from which the material (W) is discharged. The finished molded tooth (11b) is used, and the diameter (D1) on the upper side of the first mandrel (10) is slightly smaller than the diameter (D2) of the root circle of the preformed tooth (11a). A gentle slope is formed on the upstream side of the root of the tooth (11a) toward the upper side of the first mandrel (10). And the downstream side of the bottom of the preformed tooth (11a) is connected to the upstream side of the bottom of the finished molded tooth (11b) with a gentle slope, and the upstream side of the tooth tip of the preformed tooth (11a). (11a-1) is raised toward the downstream side at a predetermined inclination angle, and the raised portion is extended to the downstream side by a predetermined amount, and then the downstream end is raised at a predetermined inclination angle to form the finished molded tooth. An internal gear gold provided with a first punch (13) which is connected to the tooth tip (11b-2) of (11b) and moves the material (W) fitted in the molding space (a) downward. The internal gear is preformed by the mold device (5) , and the preformed internal gear (14) is formed by the collet (27) and the second mandrel (22) fitted to the axial center of the collet (27). ) To form an annular second molding space, and the second mand The outer peripheral surface of the collet (27) is provided with crowned molding teeth (24) at a predetermined pitch in the circumferential direction in which the tooth thickness at the axial center is thinner than the tooth thickness at both ends in the axial direction. An annular collet presser (28) is slidably fitted through a conical surface (27a) having a large diameter on the lower side, and the outer periphery of the collet presser (28) slides up and down on the second container (29). A crowning internal gear which is finish-molded by a mold device (20) of a crowning internal gear provided with a second punch (35) which can be fitted and moves the collet presser (28) downward. Molding method . The crowning molding tooth (24) is a crowning helical molding tooth, The molding method of the crowning internal gear of Claim 1 characterized by the above-mentioned.

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