Double-station cold header die

Abstract

The utility model discloses a double-station cold header die, which belongs to the technical field of bearing processing and comprises a first die and a second die, the first die comprises an upper die of the first die and a lower die of the first die, the second die comprises an upper die of the second die and a lower die of the second die, and the side wall of a cavity of the first die is an arc surface. In the forming process of an upper die and a lower die of a second die, the bottom of a preformed blank of the first die and the high point of an outer diameter arc face are clamped into a lower die cavity of the second die to be stably positioned, the ideal outer diameter of the tapered roller can be obtained, and the defect that the outer diameter is bent to form a clamping waist is overcome.

Description

Technical Field

[0001] The utility model belongs to the technical field of bearing processing, in particular to a double-station cold heading machine die. Background Art

[0002] With the continuous development and improvement of cold heading technology, single-die, single-punch cold heading machines (single-station cold heading machines) have gradually faded from the market for cold heading of medium-to-large tapered rollers. This is due to the high pressure on the die, the main die's responsibility for both material blocking and forming, the rapid expansion of the die, and the lack of quality assurance. Dual-station and multi-station cold heading machines have replaced them. Dual-station cold heading machines still utilize open-type forming, so they are less demanding on raw materials and are increasingly favored within the industry. Because the dual-station process utilizes two dies and two punches, the Z25-2 dual-station cold heading machine can process product lengths that extend from 44mm (the single-station version) to approximately 50mm, compared to the Z31-25 single-station cold heading machine.

[0003] The main molds of the Z25-2 double-station cold heading machine are composed of an upper mold, a lower mold, a second upper mold and a second lower mold. The theoretical cutting length is 60mm, and the actual cutting length can reach 62mm. The theoretical processing diameter is less than 25mm. When processing tapered rollers with an aspect ratio (ratio of material section length to material diameter) less than 2.5, the general design method can meet the requirements (the first and second mold cavities are basically the same), refer to Figure 1 and Figure 2 The first die and the second die are used as the pre-forming die, while the second die and the second die are used as the final forming die. When processing tapered rollers with a diameter greater than 14mm and an aspect ratio (ratio of material length to diameter) close to 3.3, changing the design of the first die and the second die can also meet the requirements. When the material diameter is less than 14mm and the aspect ratio is greater than 3.3 to 4, the stamping part will bend during the first die pre-forming process, and neither of the above two design methods can meet the technical requirements. Utility Model Content

[0004] The purpose of the utility model is to provide a double-station cold heading machine die, aiming to solve the problems existing in the prior art in the above background technology.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A double-station cold heading machine mold comprises a first mold and a second mold, wherein the first mold comprises an upper mold and a lower mold, and the second mold comprises an upper mold and a lower mold. The side wall of the cavity of the first mold is an arc surface.

[0007] Furthermore, the aspect ratio of the tapered roller segment is 2.5-3.2, the depth of the upper die of the single die is approximately 30%-40% of the length of the tapered roller finished product, the depth of the lower die of the single die is 60%-70% of the length of the tapered roller finished product, the depth of the upper die of the single die is complementary to the depth of the lower die of the single die, and the side wall of the cavity of the upper die of the single die is an arc surface.

[0008] Furthermore, the aspect ratio of the tapered roller segment is 3.3-4, and the cavity side walls of the upper die and the lower die are both arc surfaces.

[0009] Furthermore, the highest point of the outer diameter arc surface of the tapered roller blank after preforming by the first die should be the same as the diameter of the tangent circle at the corresponding height position of the second die.

[0010] Compared with the shortcomings and deficiencies of the prior art, the present invention has the following beneficial effects:

[0011] The utility model provides a double-station cold heading machine die, in which the side wall of a mold cavity is set as an arc surface. When the length-diameter ratio of the tapered roller material segment is 2.5-3.2, the upsetting position of the preformed blank is moved downward by lengthening the depth of the upper die of a die and shortening the depth of the lower die of a die. The side wall of the mold cavity of the upper die of a die is set as an arc surface, thereby solving the defect of incomplete outer diameter punching. When the length-diameter ratio of the tapered roller material segment is 3.3-4, the side walls of the mold cavity of the upper die of a die and the lower die of a die are both arc-shaped. The surface forces the two ends of the material segment to be positioned stably in the first die and forces the middle part to be upset and formed. During the forming process of the upper and lower dies of the second die, the bottom of the preformed blank in the first die and the high point of the outer diameter arc surface are clamped into the lower mold cavity of the second die for stable positioning, so that a more ideal outer diameter of the tapered roller can be obtained, which solves the defect of the outer diameter forming a waist due to bending. It is especially suitable for processing tapered roller segments with a diameter of ≤14mm, and fundamentally solves the problem of forming bending of tapered roller segments with extra-long taper angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of a mold structure in the prior art.

[0013] Figure 2 It is a schematic diagram of the second-mode structure in the prior art.

[0014] Figure 3 It is a schematic diagram of the upper die structure of the first die in the utility model.

[0015] Figure 4 It is a schematic diagram of the structure of the lower die of the first die in the utility model.

[0016] Figure 5 It is a schematic diagram of the second-mode structure of the utility model.

[0017] In the figure: 1. Upper die of the first die; 2. Lower die of the first die; 3. Side wall of the cavity; 4. Upper die of the second die; 5. Lower die of the second die; 6. Preform of the first die; 7. High point of the outer diameter arc surface. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Reference Figure 3-Figure 5 A double-station cold heading machine mold includes one mold and two molds. It uses a two-mold two-punch process to process tapered rollers. The one mold includes an upper mold 1 and a lower mold 2. The one mold is a pre-forming mold for processing tapered rollers. The second mold includes an upper mold 4 and a lower mold 5. The second mold is a final forming mold for processing tapered rollers.

[0020] When the diameter ratio of the tapered roller segment is 2.5-3.2, the depth D1 of the upper die 1 of the first die is 30%-40% of the length of the tapered roller finished product. Since the sum of the volume of the upper die 1 of the first die and the volume of the lower die 2 of the first die is the same as the volume of the tapered roller finished product, the volume of the upper die 1 of the first die and the volume of the lower die 2 of the first die are complementary. The depth D2 of the lower die 2 of the first die is the difference between the volume of the tapered roller finished product and the volume of the upper die 1 of the first die. Under the conditions that the mouth dimensions of the upper die 1 and the lower die 2 of the first die are the same, the bottom dimensions of the lower die 2 and the lower die 5 of the second die are the same, and the cavity angles are the same, the depth of the lower die 2 of the first die can be obtained, so that the upsetting position of the preformed segment is moved downward, which fundamentally solves the defect of incomplete outer diameter stamping. The upper model cavity side wall 3 of the upper die 1 of the first die adopts an arc surface.

[0021] When the diameter ratio of the tapered roller segment is between 3.3-4, the cavity side wall 3 of the upper die 1 of the first die and the cavity side wall 3 of the lower die 2 of the first die both adopt arc surfaces, and the high point 7 of the outer diameter arc surface of the preformed blank 6 of the first die should be the same as or slightly larger than the diameter of the tangent circle at the corresponding height position of the second die (the range of slightly larger diameter is ≤0.05mm), so that the high point 7 of the outer diameter arc surface of the preformed blank 6 of the first die abuts against the inner wall of the cavity of the lower die 5 of the second die to ensure accurate positioning during the second die forming process.

[0022] The cavity side wall 3 of the upper die 1 of the first die and the cavity side wall 3 of the lower die 2 of the first die are both arc surfaces, which are particularly suitable for when the diameter of the tapered roller segment is ≤14mm. It can effectively avoid the constraints on the two ends of the segment during the preforming process of the upper and lower dies of the first die, causing the two ends to slowly deform and forcing the middle part to become larger. During the forming process of the upper and lower dies of the second die, the bottom of the preformed blank 6 of the first die and the high point 7 of the outer diameter arc surface are clamped into the lower mold cavity of the second die for stable positioning. Since the preformed blank 6 of the first die is small at both ends and large in the middle, the bending of the segment is avoided during the forming in the upper and lower die cavities of the second die, which fundamentally solves the problem of bending of the tapered roller segment with a particularly long cone angle.

[0023] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A double-station cold heading machine mold, comprising a first mold and a second mold, both of which are used to process tapered roller segments, wherein the first mold comprises an upper mold and a lower mold, and the second mold comprises an upper mold and a lower mold, characterized in that: The side wall of the cavity of the first mold is an arc surface.

2. The double-station cold heading machine mold according to claim 1, characterized in that: The aspect ratio of the tapered roller material segment is 2.5-3.2, the depth of the upper die of the single die is approximately 30%-40% of the length of the tapered roller finished product, the depth of the lower die of the single die is 60%-70% of the length of the tapered roller finished product, the depth of the upper die of the single die is complementary to the depth of the lower die of the single die, and the side wall of the cavity of the upper die of the single die is an arc surface.

3. The double-station cold heading machine mold according to claim 1, characterized in that: The aspect ratio of the tapered roller segment is 3.3-4, and the cavity side walls of the upper die and the lower die are both arc surfaces.

4. The double-station cold heading machine mold according to claim 3, characterized in that: After preforming in one die, the highest point of the outer diameter arc surface of the tapered roller blank should be the same as the diameter of the tangent circle at the corresponding height position in the second die.

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