TECHINCAL FIELD

Embodiments of the disclosure relates to a die design and its construction, more particularly related to a replaceable die inserts for manufacturing an engine valve by metal forming process.

BACKGROUND OF THE DISCLOSURE

Existing and widely adopted designs of engine valve dies are either solid steel or tungsten carbide shrink fitted dies into a big steel casing. These dies are reused for once or twice by conversion. The steel material used for housing the carbide die are going waste and also heavy weight of the die causing fatigue on the operator to mount and dismount onto forging press (as shown in FIG. 1). The cost in manufacturing the die and engine valves is more as the die has to be replaced totally for replacing the die insert. In addition to this, as the die is no re-used for various number of forming process, the existing die design limits the usage for more number of forming processes. Another disadvantage is that the maintenance of the die is difficult as the complete tool is to be removed from the press during die change operation. The die being heavy in weight, it also induces fatigue on the operator.

SUMMARY

The shortcomings of the prior art are overcome and additional advantages are provided through the provision of die insert as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one embodiment, disclosed herein is a die (1) for manufacturing engine valve. Said die is provided with a holder (2) at bottom of the die (1). The holder comprises a top surface (2a) having a recess (2b) and a plurality of holes (2c) around the recess (2b). Further, the holder includes a bottom surface (2d) configured to mount onto a machine and a bore (2e) at its centre. The die further includes a support plate (3) mounted at the recess (2b) of the holder (2). The dies also includes a die insert (4) consisting a cavity having shape of the engine valve and is mounted over the support plate (3). An arrangement of an inner casing (5) consisting a cavity matching with shape of the die insert (4) is provided in the die for enclosing the die insert (4). The die further includes a clamping means (6) which is connected to the holder (2) using fasteners. The support plate (3), the die insert (4) and the inner casing (5) are positioned between the clamping means (6) and the holder (2).

In one embodiment, the die insert (4) is made of material selected from a group comprising Hard metals, Cermet, PM steel, and Ceramic.

In one embodiment, the Hardmetals or Cermet having a hard material phase consisting of Tungsten Carbide (WC) and/ or at least one carbide, nitride, Carbonitride, Oxicarbodnitride, at least one element of group IVa, Va, and Via of periodic table, and a binding metal phase of Fe, Co and Ni.

In one embodiment, mass percentage of said binding metal phase is ranging from about 3 to about 25.

In one embodiment, the die insert (4) is pre-stresses and is fitted with or without a split ring (7).

In one embodiment, the clamping means (6) is selected from a group comprising a cover plate with Allen screws (6a) and a cover plate with threads (6b).

In one embodiment the die insert (4) is provided with a taper, angle of taper is ranging from about 1° to about 10°.

In one embodiment, a method of assembling a die (1) comprising acts of fitting a die insert (4) into an inner casing (5) with or without split ring (7); placing a support plate (3) over a top surface (2a) of a holder (2); placing the fitted die insert (4) onto the holder (2); and fastening it with a clamping means (6) onto the holder (2).

In one embodiment, the die insert (4) is fitted with or without a split ring (7) by pushing the die insert (4) into the split ring (7).
In one embodiment, the fitted die insert (4) is pre-stressed into the inner casing.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following
detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference
numerals represent like elements and in which:

FIG. 1 shows sectional view of die according to prior art, and

FIGS. 2 and 3 show sectional views of die according to an embodiment of the disclosure,

FIG. 4 shows various views of the die according one embodiment of the disclosure,

FIG. 5 shows various views of the die according one embodiment of the disclosure,

FIG. 6 shows various views of the die according one embodiment of the disclosure,

FIG. 7 shows various views of the die according one embodiment of the disclosure, and

FIG. 8 shows various views of the die according one embodiment of the disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the disclosure.

It is to be noted at this point that all of the components, whether alone or in any combination, are claimed as being essential to the invention, in particular the details depicted in the drawings and reference numerals in the drawings are as given below.

Referral Numerals:

The disclosure is pertaining to replaceable die insert design for the engine valve manufacturing through metal forming application. The design made in the die helps to reuse the steel casing/holder for many times. The working portion of the die, i.e. die insert is a pre-stressed insert which is replaceable and reusable. The die insert is manufactured using any advanced material like hard metals, powder metal steel, ceramic or cermets.

In case of die manufactured using hard material, the die is pre-stressed by hardened and tempered steel to prevent the die from hoop-stress failure. The taper on the die inserts is ranging from about 1 degree to about 10 degrees to ensure and to apply the required pre-stress for clamping the die by the clamping means. A matching taper on clamping means is made of hardened tool steel with special surface treatment on the taper to ensure its reusability. Further, hardened support plate mounted on the holder prevents the damage which may be caused on the holder during forming process. The holder design is made in such a way that the holder self aligns the die insert with the clamping means and thereafter onto a press. The pre-stress for hardmetal die insert ensures positive clamping and reduces total die weight. Thus the reuse of steel holder for number of cycles is achieved. This in turn reduces the total cost in tooling and in manufacturing of the engine valves.

In case of dies manufactured using steel, 40% to 60% of the raw material is reused for at least 5 to 10 times or more. In case of dies manufactured using replaceable hard material, the die insert is reused for at least 2 to 3 times. The number of times the steel part being machined is also reduced considerably. Hence the cost of manufacturing of the dies and die inserts is reduced ranging from about 30% to about 50% when compared with existing design of the dies.
The die inserts are clamped either by screws or by clamps using torque wrenches. Taper angle on the die insert vary in the range from about 1 degree to about 10 degrees. The die insert is removable and re-assembling is carried out by polishing it more than 10 times.

The technology of the disclosure is further elaborated with the help of following examples. However, the examples should not be construed to limit the scope of the invention.

In an alternative embodiment, a die having Allen screw type with shrink-fitted inner casing is illustrated in FIG. 4.

The die (1) comprises a holder (2), a support plate (3), a die insert (4), an inner casing (5), and a clamping means (6). The support plate (3) is placed onto recess (2b) provided on the holder (2), then the die insert (4) is pre-stressed by the inner casing (5). Thereafter the pre-stressed die insert (4) with the inner casing (5) is placed onto the holder (2). Finally, the clamping means (6) is clamped on the holder (2) with Allen screws (8) using torque wrench. A plurality of holes (2c) provided on the top surface (2a) of the holder (2) aligns and match with the clamping means (6). The clamping means in this case is a cover plate (6a).

In an alternative embodiment, a die having Allen screw with the split-ring is illustrated in FIG. 5.

In this embodiment, the die (1) comprises a holder (2), a support plate (3), a die insert (4), a split ring (7), an inner casing (5) and a clamping means (6). The die insert (4) is push fitted into the split ring (7), then together pressed into the inner casing (5). And then placed onto the holder (2) mounted with the support plate (3). Finally the clamping means (6) is placed and fastened with the Allen screws (8) using a torque wrench.

In an alternative embodiment, a die having clamp type with shrink-fitted inner casing is illustrated in FIG. 6.

In this embodiment, the die (1) comprises a holder (2), a support plate (3), a die insert (4), an inner casing (5), and a clamping means (6). Here, the die is pre-stressed by the inner casing (5) and then the pre-stressed die (1) is placed onto the support plate (3) which is further mounted onto the holder (2). The holder (2) is provided with threads on its top portion for mounting with the clamping means (6). Finally the clamping means (6) is connected to the holder (2) using threads (8) and tighten using a torque wrench, and thus the die is ready for use.

In an alternative embodiment, a die having clamp type - with inner casing and split ring is illustrated in FIG. 7.

In this embodiment, the die (1) comprises a holder (2), a support plate (3), a die insert (4), a split ring (7), an inner casing (5) and a clamping means (6). Here, the die insert (2) is push fit into the split ring (7) and thereafter the sub assembly of the die insert (4) is push fitted into the inner casing (5). Further, the sub assembly of the inner casing (5) comprising the split ring (7), the die insert (4) is placed onto the support plate (3) which is mounted on the holder (2). The holder (2) is provided with threads on its top portion for mounting with the clamping means (6). Finally, the holder (2) is clamped with the clamping means (6) and tightened using a torque wrench. Thus the die is ready for use.

In an alternative embodiment, a die having clamp type - with split ring is illustrated in FIG. 8.

In this embodiment, the die (1) comprises a holder (2), a support plate (3), a die insert (4), a split ring (7), an inner casing (5) and a clamping means (6). Here, the die insert (4) is placed into the split ring (7) and pushed into the split ring (7). The support plate
(3) is placed on the holder (2) along with the spilt ring (7) with the die insert (2). The Holder (2) is provided with threads on its top portion for mounting with the clamping means (6). Finally, the clamping means is placed on the holder and tighten by using a torque wrench and thus the die is ready for use.

Advantages
The cost reduction in manufacturing the die and engine valves is reduced by 30 % to 50%.

As the die being re-used several times, it helps in conserving the energy and the material used in manufacturing the die and the engine valve.

The maintenance of the die is easy as the complete tool need not be removed from the press.

The die is less in weight and thereby induces less fatigue on the operator.

Better way of pre-stressing the die helps in using more wear resistant die material and their by improved performance of the die.

Equivalents With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application.

The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including
one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

We claim:

1. A die (1) for manufacturing engine valve, said die characterized in that:

a. a holder (2) at bottom of the die (1), said holder comprising:

a top surface (2a) having a recess (2b) and a plurality of holes (2c) around the recess (2b),

a bottom surface (2d) configured to mount onto a machine, a bore (2e) at its centre;

b. a support plate (3) mounted at the recess (2b) of the holder (2);

c. a die insert (4) consisting a cavity having shape of the engine valve and is mounted over the support plate (3);

d. a inner casing (5) consisting a cavity matching with shape of the die insert (4) for enclosing the die insert (4);

e. a clamping means (6) connected to the holder (2) using fasteners, wherein the support plate (3), die insert (4) and the inner casing (5) are positioned between the clamping means (6) and the holder (2).

2. The die (1) as claimed in claim 1, wherein the die insert (4) is made of material selected from a group comprising Hard metals, Cermet, PM steel, and Ceramic.

3. The die (1) as claimed in claim 2, wherein the hard metals or Cermet is having a hard material phase consisting of Tungsten Carbide (WC) and at least one carbide, nitride, Carbonitride, Oxicarbodnitride, at least one element of group IVa, Va, and Via of periodic table, and a binding metal phase of Fe, Co and Ni.

4. The die (1) as claimed in claim 3, wherein mass percentage of said binding metal phase is ranging from about 3 to about 25.

5. The die (1) as claimed in claim 1, wherein the die insert (4) is pre-stresses and is fitted with or without a split ring (7).

6. The die (1) as claimed in claim 1, wherein the clamping means (6) is selected from a group comprising a cover plate with Allen screws (6a) and a cover plate with threads (6b).

7. The die (1) as claimed in claim 1, wherein the die insert (4) is provided with a taper, angle of taper is ranging from about 1° to about 10°.

8. A method of assembling a die (1) as claimed in claim 1, said method comprising acts of:

a. fitting a die insert (4) into an inner casing (5);

b. placing a support plate (3) over a top surface (2a) of a holder (2);

c. placing the fitted die insert (4) onto the holder (2); and

d. fastening a clamping means (6) onto the holder (2).

9. The method as claimed in claim 8, wherein the die insert (4) is fitted with or without a split ring (7) by pushing the die insert (4) into the split ring (7).

10. The method as claimed in claim 9, wherein the fitted die insert (4) is pre-stressed by the inner casing.