阅读说明：本技术 内齿轮粉末冶金用成型模具 (Forming die for internal gear powder metallurgy ) 是由 宁上中 于 2019-10-28 设计创作，主要内容包括：本发明公开了一种成型细致、成品使用性能佳的内齿轮粉末冶金用成型模具,包括中模座、用于成型工件上表面的上冲、下冲、穿设在下冲中部轴向通孔中的芯棒,中模座中设有中模芯,中模芯内上段上周向均布有若干成型工件外周间隔块的外成型槽口,中模芯内中段为圆形光滑内壁,上冲中活动穿设有上二冲,上二冲下部设有一圈用于成型工件内部齿牙的成型槽,下冲轴向通孔的上部孔壁设有若干与成型槽相配合的导向成型块,导向成型块的顶部为呈倾斜状以成型工件齿牙端部斜面,中模芯下段内壁上周向布置有若干定位槽,下冲上部外侧设有若干卡入定位槽的定位凸块；芯棒上段外侧周向设有若干卡入下冲内壁上导向成型块之间间隙中的预定型块。(The invention discloses a forming die for powder metallurgy of an internal gear, which has fine forming and good use performance of a finished product, and comprises a middle die holder and an upper punch used for forming the upper surface of a workpiece, the lower punch is arranged on the upper section of the middle die core in a circumferential and uniform distribution mode, the middle section of the middle die core is a round smooth inner wall, the upper punch is movably provided with an upper punch, the lower part of the upper punch is provided with a circle of forming grooves for forming teeth inside the workpiece, the upper hole wall of the lower punch axial through hole is provided with a plurality of guide forming blocks matched with the forming grooves, the top of each guide forming block is an inclined plane for forming the end parts of the teeth of the workpiece, the inner wall of the lower section of the middle die core is circumferentially provided with a plurality of positioning grooves, and the outer side of the upper part of the lower punch is provided with a plurality of positioning lugs clamped into the positioning grooves; a plurality of preset blocks clamped into gaps between the guide forming blocks on the inner wall of the lower punch are arranged on the outer side of the upper section of the core rod in the circumferential direction.)

1. Internal gear is forming die for powder metallurgy, its characterized in that: the feeding device comprises a middle die holder, an upper punch, a lower punch and a core rod, wherein the upper punch, the lower punch and the core rod are used for forming the upper surface of a workpiece, the core rod is arranged in an axial through hole in the middle of the lower punch in a penetrating manner, a middle die core used for forming the outer side surface of the workpiece is detachably arranged in the middle die holder, a plurality of outer forming notches of peripheral spacing blocks of the formed workpiece are uniformly distributed on the upper section of the middle die core in the circumferential direction, the middle section of the middle die core is a round smooth;

an upper punch is movably arranged in the upper punch in a penetrating manner, a circle of forming groove used for forming teeth inside the workpiece is arranged at the lower part of the upper punch, a plurality of guide forming blocks matched with the forming groove are arranged on the upper hole wall of the lower punch axial through hole, the top of each guide forming block is an inclined surface for forming the end part inclined surface of the tooth of the workpiece, and the lower part of the upper punch is inserted into the lower punch axial through hole to be matched with the middle die core and the lower surface of the upper punch to form a forming cavity of the formed workpiece; a plurality of vertical positioning grooves for guiding and positioning the lower punch and the upper punch are circumferentially arranged on the inner wall of the lower section of the middle mold core, and a plurality of positioning lugs clamped into the positioning grooves are arranged on the outer side of the upper part of the lower punch; a plurality of preset blocks clamped into gaps between the guide forming blocks on the inner wall of the lower punch are arranged on the outer side of the upper section of the core rod in the circumferential direction.

Technical Field

The invention relates to a forming die for powder metallurgy of an internal gear.

Background

In the internal gear shown in fig. 1 and 2, when the powder metallurgy processing is adopted, the traditional method of powder blank is to punch and form by adopting the structure of an upper punch, a middle die, a lower punch and a core rod. After the workpiece powder blank is sintered, a circle of groove on the periphery needs to be machined.

However, with the structure, the arc angle of the inner teeth of the workpiece can not be made, the inner gear ring is used for engaging gears, and if the inner teeth do not have round corners, the gear disengaging condition can occur in actual use, so that the use performance is seriously influenced.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the forming die for the powder metallurgy of the internal gear is fine in forming and good in service performance of a finished product.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: the forming die for powder metallurgy of the internal gear comprises a middle die holder, an upper punch, a lower punch and a core rod, wherein the upper punch and the lower punch are used for forming the upper surface of a workpiece, the core rod is arranged in an axial through hole in the middle of the lower punch in a penetrating manner, a middle die core for forming the outer side surface of the workpiece is detachably arranged in the middle die holder, a plurality of outer forming notches of peripheral spacing blocks of the formed workpiece are uniformly distributed on the upper section in the middle die core in the circumferential direction, the middle section in the middle die core is a round smooth inner wall, and the,

an upper punch is movably arranged in the upper punch in a penetrating manner, a circle of forming groove used for forming teeth inside the workpiece is arranged at the lower part of the upper punch, a plurality of guide forming blocks matched with the forming groove are arranged on the upper hole wall of the lower punch axial through hole, the top of each guide forming block is an inclined surface for forming the end part inclined surface of the tooth of the workpiece, and the lower part of the upper punch is inserted into the lower punch axial through hole to be matched with the middle die core and the lower surface of the upper punch to form a forming cavity of the formed workpiece; a plurality of vertical positioning grooves for guiding and positioning the lower punch and the upper punch are circumferentially arranged on the inner wall of the lower section of the middle mold core, and a plurality of positioning lugs clamped into the positioning grooves are arranged on the outer side of the upper part of the lower punch; a plurality of preset blocks clamped into gaps between the guide forming blocks on the inner wall of the lower punch are arranged on the outer side of the upper section of the core rod in the circumferential direction.

The invention has the beneficial effects that:

because the middle die core is used for forming the outer side surface of a workpiece, a plurality of outer forming notches of the forming workpiece periphery spacing blocks are uniformly distributed on the upper section of the middle die core in the circumferential direction, the middle section of the middle die core is a round smooth inner wall, the core rod is matched with the lower punch and the middle die core to form a feeding cavity for feeding, the upper punch is movably penetrated and provided with the upper punch, the lower part of the upper punch is provided with a forming groove for forming teeth inside the workpiece, the round angle of the inner teeth of the workpiece can be accurately formed, and therefore the product is good in use performance. The upper hole wall of the lower punch axial through hole is provided with a plurality of guide forming blocks matched with the forming grooves, the top of each guide forming block is an inclined surface for forming the end part inclined surface of the tooth of the workpiece, and the core rod moves downwards while the lower parts of the upper punches are inserted into the lower punch axial through hole to be matched with the middle mold core and the lower surface of the upper punch to form a forming cavity of the formed workpiece; because the outer side of the upper section of the mandrel is circumferentially provided with a plurality of preset forming blocks clamped into gaps between the guide forming blocks on the inner wall of the lower punch, the mandrel can preset the inner hole of the workpiece, iron powder can be prevented from scattering, and the forming precision of the workpiece is ensured.

A plurality of vertical positioning grooves used for guiding and positioning the lower punch moving up position are circumferentially arranged on the inner wall of the lower section of the middle mold core, and a plurality of positioning lugs clamped into the positioning grooves are arranged on the outer side of the upper part of the lower punch, so that the lower punch can move more stably, and can conveniently, quickly and accurately move in place in the vertical direction.

Drawings

FIG. 1 is a schematic front view of a processed product of the present invention.

FIG. 2 is a schematic sectional view of a worked product of the present invention.

Fig. 3 is a schematic front view of the present invention.

FIG. 4 is a schematic top view of an undershoot in the present invention.

Fig. 5 is a schematic view of the inner cross section of the upper section of the center core in the present invention.

In fig. 3 to 5: 1. the forming die comprises a middle die holder, 2. an upper punch, 3. a lower punch, 31. a guide forming block and 32. a positioning lug; 4. core rod, 5, middle mold core, 6, two punching.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 3-5, the forming die for powder metallurgy of internal gear comprises a middle die holder 1, an upper punch 2 used for forming the upper surface of a workpiece, a lower punch 3, and a core rod 4 inserted into an axial through hole in the middle of the lower punch 3, wherein a middle die core 5 used for forming the outer side surface of the workpiece is detachably arranged in the middle die holder 1, a plurality of outer forming notches of peripheral spacing blocks of the formed workpiece are circumferentially and uniformly distributed on the upper section in the middle die core 5, the middle section in the middle die core 5 is a circular smooth inner wall, and the core rod 4, the lower punch 3 and the middle die core 5 are matched to form a feeding cavity for feeding;

an upper punch 6 is movably arranged in the upper punch 2 in a penetrating mode, a circle of forming groove used for forming teeth inside a workpiece is formed in the lower portion of the upper punch 6, a plurality of guide forming blocks 31 matched with the forming groove are arranged on the upper hole wall of an axial through hole of the lower punch 3, the top of each guide forming block 31 is an inclined surface used for forming the end portion of each tooth of the workpiece, and the lower portion of the upper punch 6 is inserted into the axial through hole of the lower punch 3 to be matched with the middle die core 5 and the lower surface of the upper punch 2 to form a forming cavity of the formed workpiece when the core rod 4 moves downwards; a plurality of vertical positioning grooves for guiding and positioning the upward movement position of the lower punch 3 are circumferentially arranged on the inner wall of the lower section of the middle mold core 5, and a plurality of positioning lugs 32 clamped into the positioning grooves are arranged on the outer side of the upper part of the lower punch 3; a plurality of preset blocks clamped into the gaps between the guide forming blocks 31 on the inner wall of the lower punch 3 are arranged on the outer side of the upper section of the core rod 4 in the circumferential direction.

After the workpiece powder blank is sintered, a circle of groove on the periphery still needs to be machined.

The above-mentioned embodiments are merely illustrative of the principles and effects of the present invention, and some embodiments may be used, not restrictive; it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications belong to the protection scope of the present invention.