JP6564357B2 - Gear mold - Google Patents

Description

  The present invention relates to a gear mold that can stably mass-produce a helical gear and a gear with a crowning by preventing damage to a tooth profile, deterioration of product accuracy, and shortening of a mold life.

  For material filling of the helical gear (helical gear) mold, forging production described in, for example, Patent Documents 1 to 5 has been proposed by an extrusion method, a diversion method, or the like. In addition, about the patent documents 1-5 described below, description is unified into this application term.

  Patent Document 1 discloses that a rough tooth that can be press-fitted into a gear formed tooth is formed by slidably fitting a die having a gear formed tooth on the inner periphery and a tapered surface on the outer periphery into a taper hole of a die holder. A formed coarse gear is provided, and a first punch for press-fitting the coarse gear into the die from one end to the other end on the large diameter side, located on the reverse side with respect to the first punch, and of the die A gear finishing forging device has been proposed in which a second punch capable of contacting the end surface on the large-diameter side is provided, and a resistance device that provides resistance to movement in the small-diameter direction through the tapered hole of the die is provided.

  Patent Document 2 includes a cylindrical die having a plurality of tooth profile forming grooves into which respective teeth of a material are fitted and through which a die hole having the same cross-sectional shape passes in the axial direction, and has a base end side and a top end side of the die. A gear with crowned teeth is formed by elastic contraction, and then a gear with crowning is formed by elastically restoring the die by releasing elastic contraction and extracting the gear from the expanded die hole. It has been proposed to do.

  Patent Document 3 is provided with a finish mold in which the side surfaces of the inner teeth are formed in an anti-crown shape, and a primary gear in which the outer teeth are formed to have substantially the same tooth thickness over the entire length, and the finish mold is used as a clamp. In addition to the taper fitting, the shaft end of the finishing mold with the taper surface having a large diameter is brought into contact with the stopper die, and each tooth of the primary gear is fitted between each tooth of the finishing mold. Is moved in the axial direction where the taper surface has a large diameter with respect to the finish mold, the finish mold is elastically deformed to a small diameter, and each tooth of the primary gear is pressed against each tooth of the primary gear. It has been proposed to form in a crown shape.

  Patent Document 4 prepares a workpiece which is a cylindrical gear having a tooth profile without crowning in advance, and has a cylindrical tooth profile on the inside, an upper engagement surface and a lower engagement surface on the outer side, and an elastic deformation type. , The lower engagement surface of the mold is set to a ring with a tapered hole, and the lower portion of the cylindrical tooth shape of the mold is elastically modified so that the pitch circle is along an arc-shaped curved surface in the axial direction, The upper part of the cylindrical tooth profile of the mold remains cylindrical, and the workpiece is inserted into the mold. First, the lower part of the mold is crowned at the lower part of the mold that is elastically deformed. The tooth profile is formed by cold forging. At that time, the upper part of the comparative product remains in a cylindrical shape without crowning, and then the inner taper of the outer punch is pressed against the upper engagement surface of the mold to It is elastically deformed inward, and the upper part of the workpiece has a crownin The urging teeth have been proposed to mold by cold forging.

  Patent Document 5 discloses that a tooth profile die includes a gear tooth guide portion for forming gear teeth formed on an upper end portion, and a gear tooth formed integrally with the gear tooth forming portion extending downward from the gear tooth forming portion. And a gear tooth guide part capable of forming a minute clearance with the outer surface of the gear tooth, and the mandrel has a minute part formed on the outer periphery of the mandrel halfway part spaced downward from the lower end of the punch. When a gear is forged by a forging device having an annular recess of depth, all or part of the material filled in the annular recess is forced to flow to the peripheral wall of the gear via the mandrel ascending operation. It has been proposed to form crowning.

  Although it is possible to manufacture helical gears, in particular, helical gears with crowning, by the forging methods of the prior art and Patent Documents 1 to 5 above, there are mainly the following problems 1 to 3 at the time of discharging the molded product, which are still at a practical level. In fact, most of them are still being processed by cutting.

1: A right-angle force is applied to the tooth profile at the time of knockout, and the tooth profile is damaged and the life of the mold is extremely short. Knockout drainage is extremely difficult if a crowning shape is used to make the end of the muscle slightly thinner (or slightly thicker in the central part in the axial direction of the tooth muscle)

  For the above 1 and 2, a method of canceling the vertical force applied to the teeth to some extent by applying torsional force at the time of knockout has also been proposed, but the tooth profile part of the product immediately after the end of deformation is a mold Therefore, it is difficult to knock out by adding only a torsional force.

  As for the above 3, in Patent Documents 1 to 5, the tooth shape is elastically deformed by applying a force and molded into a crowning shape, and then the elastic deformation of the mold is released to knock out. When the mold is elastically deformed, there is a problem that a load is applied to the mold, the mold life is reduced, and stable mass production cannot be performed.

JP 2005-7468 A JP 2007-54874 A JP 2007-203374 A JP 2011-16162 A JP 2014-217876 A

  The problem to be solved is that when gears, especially helical gears and gears with crowning are manufactured by (cold) forging, a force perpendicular to the tooth profile is applied at the time of knockout (discharge) after molding, causing damage to the tooth profile. The service life of the mold is remarkably shortened, the tooth profile is elastically deformed and the material is plastically deformed, and the product accuracy is deteriorated. Further, when the crowning shape is applied, knockout discharge itself is extremely difficult.

In order to solve the above-described problems, the present invention is a mold for manufacturing a gear, and a tooth root forming portion protruding in the center direction for forming a gear tooth root of a planned gear, and a tooth of the planned gear In order to form the top surface of the crest by dividing it into two in the circumferential direction, the tooth crest forming portion formed on each of the hem portions on one side and the other side in the circumferential direction centered on the tooth root forming portion was provided. possess only the number of teeth of the gear demarcating the die gauge, said die, from the center of the material to be produced gear, Hayama molding of each of the one side and the other side in the circumferential direction around the Hatani molding portion Section obtained by rotating in a circumferential direction a range defined by a dividing line extending a predetermined length in a radially outward direction from a dividing point that divides the top surface of a gear tooth planned in a section in the circumferential direction The main feature is that a support portion having a shape is formed .

  The gear mold of the present invention is composed of a plurality of dies divided by the number of gear teeth, and further, the die of the gear to be manufactured is divided into two by adjacent dies. By opening the die in the radially outward direction perpendicular to the axis and opening the entire mold, the die tooth profile forming part can easily release the tightening force on the gear tooth profile part, and therefore by knockout In addition to facilitating product discharge from the mold, no stress is applied to the mold (die) at the time of knockout, so the life of the mold can be prevented from being shortened and stable mass production is possible.

It is a figure which shows the helical gear with a crowning obtained with the gear metal mold | die of this invention. The die in the gear metal mold | die of this invention is shown, (a) is a front direction, (b) is a back direction, (c) is a left side direction, (d) is a right side direction, (e) is a plane direction, (f ) Are views seen from the bottom direction. (A) is a figure for demonstrating the shape of the die | dye in the gear metal mold | die of this invention, (b) is the sectional view on the AA line in (a), (c) is the sectional view on the BB line in (a). It is. It is a figure which shows the condition before shape | molding after shape | molding a gear with the gear metal mold | die of this invention of this invention. (A)-(d) is the figure which showed the forge molding procedure of the gear using the gear metal mold | die of this invention, (e)-(h) is the forging equipment in each time of (a)-(d). It is the figure which showed the direction of a motion and force.

  According to the present invention, when gears, especially helical gears or gears with crowning are manufactured by (cold) forging, the tooth profile is damaged and the life of the die is significantly shortened, and the tooth profile is elastically deformed and the material is plastically deformed. The accuracy of the product deteriorates, and if the crowning shape is applied, knockout discharge itself is extremely difficult. The tooth root forming part protruding in the center direction to form the tooth root of the planned gear and the planned gear To form the tooth crest top surface into two parts in the circumferential direction, there are tooth crest forming parts formed at both the hem part on one side and the other side in the circumferential direction around the tooth root forming part. The same shape die was overcome by having the planned number of gear teeth.

Also, dialog of the present invention, from the center of the material to be produced gear of the gear to plan in Hayama forming part of each of the one side and the other side in the circumferential direction around the Hatani forming portion Hayama A support portion having a cross-sectional shape obtained by rotating in a circumferential direction a range defined by a dividing line extending a predetermined length in a radially outward direction from a dividing point at which the top surface of the substrate is divided in the circumferential direction is formed. According to the configuration , the entire die can be easily arranged, the force from the mold can be equally applied to the gear material in the axial direction, and an optional jig for the opening / closing operation of the gear mold can be easily provided.

  Hereinafter, the gear mold of the present invention will be described with reference to FIGS. In the gear mold 1 of the present invention, in FIG. 1 to FIG. 5, the end face of the gear G is given a dot-like hatching even if it is not a cross section. In the present embodiment, description will be made on the assumption that a helical gear G with a crowning C as shown in FIG. 1 (hereinafter referred to as gear G) is manufactured. The gear mold 1 is composed of a plurality of dies 2 divided into the number of teeth of the gear G to be manufactured.

  The die 2 is formed by dividing the tooth root forming portion 2v projecting in the center direction and forming the top surface of the tooth crest Gm of the planned gear G into the circumferential direction in order to form the root Gv of the planned gear G. For this purpose, tooth crest forming portions 2m and 2m formed at both hem portions on one side and the other side in the circumferential direction centering on the tooth root forming portion 2v are provided. As described above, the die 2 has the same number of teeth (mounts) Gm of the planned gear G, all of which have the same shape.

  Further, as shown in FIG. 2 (b), the tooth crest forming portions 2m and 2m in the die 2 are narrowed between the tooth crest forming portions 2m and 2m of the adjacent die 2 at both end portions in the axial direction. A narrow portion 2 ms is formed, and a central portion is a widened portion 2 mb. That is, the gear mold 1 of this example forms the tooth crest Gm with crowning C by the narrow portions 2 ms and 2 ms of the tooth crest forming portions 2 m and 2 m of the adjacent dies 2 and 2 and the wide portions 2 mb and 2 mb. The configuration is shown.

  Further, as shown in FIG. 3, the die 2 includes a tooth profile forming portion 2 m on one side and a tooth profile on the other side from the center of the material for which the gear G is to be manufactured. A support portion that is a range defined by dividing lines P1 and P2 extending at a predetermined angle in a radially outward direction from a dividing point that divides the top surface of the gear tooth tooth Gv to be planned in the molding portion 2m in the circumferential direction. 2X is formed.

  As shown in FIGS. 3B and 3C, the die 2 has a shape of the support portion 2X portion that is a range defined by the imaginary lines P1 and P2 in any cross section (end face) at any height position in the axial direction. With regard to, the same cross-sectional shape is used in any axial cross-section of any die 2, so that a uniform clamping force can be applied to the material for which the gear G is to be manufactured.

  The die 2 of the present example has a support portion 2X, so that a slope with a downward slope is formed from above to below in order to fit a high-speed ring 5 described later on the outer peripheral surface of the support portion 2X in a state where the die 2 is arranged and arranged. A guide 2B for forming or forming a taper 2A for fitting the mold opening jig 3 on the end surface above the support portion 2X, or guiding the movement of the die 2 to the end surface below the support portion 2X Or can be provided.

  That is, the die 2 has a tooth profile forming portion 2m on the one side and the other side in the circumferential direction centering on the tooth root forming portion 2m (narrow portions 2ms, 2ms and wide portions 2mb, 2mb are formed in the axial direction, respectively). , 2m, the support portion 2X is formed in the radially outward direction, and the range defined by the dividing lines P1 and P2 (support portion 2X) is divided from the cylindrical mold material while rotating in the circumferential direction. It has a shape like that.

  The description of the individual “shape” of the die 2 is as described above. However, regarding the “production” of the actual die 2, it is not divided from the cylindrical mold material as described above, for example, One mockup of the die 2 is created by a method such as cutting, and the number of tooth teeth Gm of the gear G is normally produced based on this mockup.

  As described above, the die 2 of this example is expanded in diameter by being inserted into the mold opening jig 3 (FIG. 5) on one end side in the axial direction (assumed to be the upper side) of the support portion 2X. The taper 2A for guiding the die 2 in the direction is fixed to the other end side (below) guided by the rail 4A of the die placement table 4 (FIG. 5) so that the die 2 does not spread when the mold is opened and closed. A guide 2B for moving in the direction of diameter expansion and contraction while maintaining the standing posture is formed.

  The gear mold 1 in the present example is operated as shown in FIG. In FIG. 5, (a) to (d) are perspective views of the peripheral forging facilities that are required centering on the gear mold 1 of the present invention, and (e) to (h) are (a) to (d) respectively. Only one radius in the radial direction of the gear G is shown in the schematic diagram showing the state of the force applied by the peripheral forging equipment in the process.

5 (a) and 5 (e)
The guide 2B of the die 2 is inserted into the rail 4A of the die arrangement table 4 to arrange all the dies 2, and the restraining ring 5 is inserted into the outer peripheral surface of the arranged die 2 to obtain the gear mold 1. The constraining ring 5 is for collecting and fixing the dies 2 on the die placement table 4 in the radial center direction so that the dies 2 are in close contact with each other without a gap. The die 2 of this example is formed with a slope having a downward slope from above the outer periphery of the support portion 2X. When the restraining ring 5 is inserted from above the gear mold 1 and moved downward, the die 2 is moved. They are in close contact with each other. Thereafter, in this example, the material of the cylindrical gear G is disposed between the gear molds 1.

5B and 5F
After the above, the punch 6 is lowered from the opposite side of the die placement table 4 in the axial direction, that is, from above, and the material of the gear G inserted into the gear mold 1 is pressed downward. At this time, the material of the gear G receives the pressing force of the punch 6, and the tooth crest Gv is formed in the tooth crest forming portions 2m and 2m, the tooth crest Gv is formed in the tooth crest forming portion 2v, and the gaps in the tooth crest forming portions 2m and 2m. The crowning C is formed by plastic deformation by the portions 2 ms and 2 ms and the expanded portions 2 mb and 2 mb, respectively.

FIG. 5 (c) (g)
When the molding by the punch 6 is completed, the restraining ring 5 is removed from the outer periphery of the gear mold 1, and then the mold opening jig 3 is inserted toward the gear mold 1. The mold opening jig 3 is formed with a slope along the taper 2A of the die 2, and when the mold opening jig 3 is inserted into the gear mold 1, it is brought into contact with the taper 2A and guided to the slope. This is for moving the die 2 in the diameter expanding direction. In this state, all the dies 2 (gear molds 1) are separated from the tooth roots Gv and the tooth ridges Gm of the gear G in the radially outward direction to be in the mold open state. Specifically, the dies 2 move radially, and the circumferential interval between them is increased. At this time, the adjacent tooth crest forming portions 2m and 2m are separated from each other in the circumferential direction with respect to one tooth crest Gm. The mold will open as you do.

FIG. 5 (d) (h)
After the above, by raising the knockout pin 7 from below the gear mold 1 via the die placement table 4, the gear G that is a molded product (helical with a crowning C) is discharged. At this time, according to the gear mold 1 of the present invention, the knockout pin 7 does not have to hold the gear G and rotate in the circumferential direction, and the gear G is not already in contact with the mold in the mold open state. It is only necessary to raise the knockout pin 7 as it is.

  In the above description, the gear mold 1 of the present invention has been described as an example used when the gear G is molded from an unmolded material. However, for example, a crowning C or a plan is made for a semi-finished material. You may use in the last shaping | molding process for setting it as tooth tooth Gm.

  As described above, the gear mold 1 of the present invention has the dies 2 that move in the diameter-expanding direction when the mold is opened, as many as the number of tooth teeth Gm. Therefore, when the molded gear G is knocked out and discharged from the mold. There is no load applied to the mold and the gear G. As a result, the life of the gear mold 1 can be extended, deformation of the gear G can be reduced, and stable mass production can be achieved.

DESCRIPTION OF SYMBOLS 1 Gear metal mold | die 2v Tooth root forming part 2m Tooth crest forming part 2ms Narrow part 2mb Widening part 2A Taper 2B Guide 2X Support part G (Helical) gear Gv Tooth Gm Tooth C C Crowning

Claims (1)

A mold for manufacturing a gear, in which a tooth root forming portion protruding in the central direction to form a tooth root of the planned gear and a top surface of the tooth peak of the planned gear are divided into two in the circumferential direction. teeth of the tooth valley demarcating molded part and Hayama molding portion formed on both the skirt portion of the one side and the other side of the center and the circumferential direction, the die of the same shape having a total gear for molding Te possess only a few, the die, the center of the material to be produced gear of the gear to plan in Hayama forming part of each of the one side and the other side in the circumferential direction around the Hatani forming portion Hayama A support portion having a cross-sectional shape obtained by rotating in a circumferential direction a range defined by a dividing line extending a predetermined length in a radially outward direction from a dividing point dividing the top surface of the substrate in a circumferential direction is formed. gear mold, characterized in that there.

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